diff --git a/lib/chibi/base64.module b/lib/chibi/base64.module
new file mode 100644
index 00000000..12324e1d
--- /dev/null
+++ b/lib/chibi/base64.module
@@ -0,0 +1,7 @@
+
+(define-module (chibi base64)
+  (export base64-encode base64-encode-string
+          base64-decode base64-decode-string
+          base64-encode-header)
+  (import-immutable (scheme) (srfi 33) (chibi io))
+  (include "base64.scm"))
diff --git a/lib/chibi/base64.scm b/lib/chibi/base64.scm
new file mode 100644
index 00000000..3d95ad71
--- /dev/null
+++ b/lib/chibi/base64.scm
@@ -0,0 +1,351 @@
+;; Copyright (c) 2005-2009 Alex Shinn.  All rights reserved.
+;; BSD-style license: http://synthcode.com/license.txt
+
+;; Procedure: base64-encode-string str
+;;   Return a base64 encoded representation of string according to the
+;;   official base64 standard as described in RFC3548.
+
+;; Procedure: base64-decode-string str
+;;   Return a base64 decoded representation of string, also interpreting
+;;   the alternate 62 & 63 valued characters as described in RFC3548.
+;;   Other out-of-band characters are silently stripped, and = signals
+;;   the end of the encoded string.  No errors will be raised.
+
+;; Procedure: base64-encode [port]
+;; Procedure: base64-decode [port]
+;;   Variations of the above which read and write to ports.
+
+;; Procedure: base64-encode-header enc str [start-col max-col nl]
+;;   Return a base64 encoded representation of string as above,
+;;   wrapped in =?ENC?B?...?= as per RFC1522, split across multiple
+;;   MIME-header lines as needed to keep each lines length less than
+;;   MAX-COL.  The string is encoded as is, and the encoding ENC is
+;;   just used for the prefix, i.e. you are responsible for ensuring
+;;   STR is already encoded according to ENC.  The optional argument
+;;   NL is the newline separator, defaulting to CRLF.
+
+;; This API is compatible with the Gauche library rfc.base64.
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; string utils
+
+(define (string-chop str n)
+  (let ((len (string-length str)))
+    (let lp ((i 0) (res '()))
+      (let ((j (+ i n)))
+        (if (>= j len)
+            (reverse (cons (substring str i len) res))
+            (lp j (cons (substring str i j) res)))))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; constants and tables
+
+(define *default-max-col* 76)
+
+(define *outside-char* 99) ; luft-balloons
+(define *pad-char* 101)    ; dalmations
+
+(define *base64-decode-table*
+  (let ((res (make-vector #x100 *outside-char*)))
+    (let lp ((i 0)) ; map letters
+      (cond
+       ((<= i 25)
+        (vector-set! res (+ i 65) i)
+        (vector-set! res (+ i 97) (+ i 26))
+        (lp (+ i 1)))))
+    (let lp ((i 0)) ; map numbers
+      (cond
+       ((<= i 9)
+        (vector-set! res (+ i 48) (+ i 52))
+        (lp (+ i 1)))))
+    ;; extras (be liberal for different common base64 formats)
+    (vector-set! res (char->integer #\+) 62)
+    (vector-set! res (char->integer #\-) 62)
+    (vector-set! res (char->integer #\/) 63)
+    (vector-set! res (char->integer #\_) 63)
+    (vector-set! res (char->integer #\~) 63)
+    (vector-set! res (char->integer #\=) *pad-char*)
+    res))
+
+(define (base64-decode-char c)
+  (vector-ref *base64-decode-table* (char->integer c)))
+
+(define *base64-encode-table*
+  (let ((res (make-vector 64)))
+    (let lp ((i 0)) ; map letters
+      (cond
+       ((<= i 25)
+        (vector-set! res i (integer->char (+ i 65)))
+        (vector-set! res (+ i 26) (integer->char (+ i 97)))
+        (lp (+ i 1)))))
+    (let lp ((i 0)) ; map numbers
+      (cond
+       ((<= i 9)
+        (vector-set! res (+ i 52) (integer->char (+ i 48)))
+        (lp (+ i 1)))))
+    (vector-set! res 62 #\+)
+    (vector-set! res 63 #\/)
+    res))
+
+(define (enc i)
+  (vector-ref *base64-encode-table* i))
+
+;; try to match common boundaries
+(define decode-src-length
+  (lcm 76 78))
+
+(define decode-dst-length
+  (* 3 (arithmetic-shift (+ 3 decode-src-length) -2)))
+
+(define encode-src-length
+  (* 3 1024))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; decoding
+
+;; Create a result buffer with the maximum possible length for the
+;; input, and pass it to the internal base64-decode-string! utility.
+;; If the resulting length used is exact, we can return that buffer,
+;; otherwise we return the appropriate substring.
+(define (base64-decode-string src)
+  (let* ((len (string-length src))
+         (dst-len (* 3 (arithmetic-shift (+ 3 len) -2)))
+         (dst (make-string dst-len)))
+    (base64-decode-string!
+     src 0 len dst
+     (lambda (src-offset res-len b1 b2 b3)
+       (let ((res-len (base64-decode-finish dst res-len b1 b2 b3)))
+         (if (= res-len dst-len)
+             dst
+             (substring dst 0 res-len)))))))
+
+;; This is a little funky.
+;;
+;;   We want to skip over "outside" characters (e.g. newlines inside
+;;   base64-encoded data, as would be passed in mail clients and most
+;;   large base64 data).  This would normally mean two nested loops -
+;;   one for overall processing the input, and one for looping until
+;;   we get to a valid character.  However, many Scheme compilers are
+;;   really bad about optimizing nested loops of primitives, so we
+;;   flatten this into a single loop, using conditionals to determine
+;;   which character is currently being read.
+(define (base64-decode-string! src start end dst kont)
+  (let lp ((i start)
+           (j 0)
+           (b1 *outside-char*)
+           (b2 *outside-char*)
+           (b3 *outside-char*))
+    (if (>= i end)
+        (kont i j b1 b2 b3)
+        (let ((c (base64-decode-char (string-ref src i))))
+          (cond
+           ((eqv? c *pad-char*)
+            (kont i j b1 b2 b3))
+           ((eqv? c *outside-char*)
+            (lp (+ i 1) j b1 b2 b3))
+           ((eqv? b1 *outside-char*)
+            (lp (+ i 1) j c b2 b3))
+           ((eqv? b2 *outside-char*)
+            (lp (+ i 1) j b1 c b3))
+           ((eqv? b3 *outside-char*)
+            (lp (+ i 1) j b1 b2 c))
+           (else
+            (string-set! dst
+                         j
+                         (integer->char
+                          (bitwise-ior (arithmetic-shift b1 2)
+                                       (extract-bit-field 2 4 b2))))
+            (string-set! dst
+                         (+ j 1)
+                         (integer->char
+                          (bitwise-ior
+                           (arithmetic-shift (extract-bit-field 4 0 b2) 4)
+                           (extract-bit-field 4 2 b3))))
+            (string-set! dst
+                         (+ j 2)
+                         (integer->char
+                          (bitwise-ior
+                           (arithmetic-shift (extract-bit-field 2 0 b3) 6)
+                           c)))
+            (lp (+ i 1) (+ j 3)
+                *outside-char* *outside-char* *outside-char*)))))))
+
+;; If requested, account for any "partial" results (i.e. trailing 2 or
+;; 3 chars) by writing them into the destination (additional 1 or 2
+;; bytes) and returning the adjusted offset for how much data we've
+;; written.
+(define (base64-decode-finish dst j b1 b2 b3)
+  (cond
+   ((eqv? b1 *outside-char*)
+    j)
+   ((eqv? b2 *outside-char*)
+    (string-set! dst j (integer->char (arithmetic-shift b1 2)))
+    (+ j 1))
+   (else
+    (string-set! dst
+                 j
+                 (integer->char
+                  (bitwise-ior (arithmetic-shift b1 2)
+                               (extract-bit-field 2 4 b2))))
+    (cond
+     ((eqv? b3 *outside-char*)
+      (+ j 1))
+     (else
+      (string-set! dst
+                   (+ j 1)
+                   (integer->char
+                    (bitwise-ior
+                     (arithmetic-shift (extract-bit-field 4 0 b2) 4)
+                     (extract-bit-field 4 2 b3))))
+      (+ j 2))))))
+
+;; General port decoder: work in single blocks at a time to avoid
+;; allocating memory (crucial for Scheme implementations that don't
+;; allow large strings).
+(define (base64-decode . o)
+  (let ((in (if (pair? o) (car o) (current-input-port)))
+        (out (if (and (pair? o) (pair? (cdr o)))
+                 (cadr o)
+                 (current-output-port))))
+    (let ((src (make-string decode-src-length))
+          (dst (make-string decode-dst-length)))
+      (let lp ((offset 0))
+        (let ((src-len (+ offset
+                          (read-string! decode-src-length src in offset))))
+          (cond
+           ((= src-len decode-src-length)
+            ;; read a full chunk: decode, write and loop
+            (base64-decode-string!
+             src 0 decode-src-length dst
+             (lambda (src-offset dst-len b1 b2 b3)
+               (cond
+                ((and (< src-offset src-len)
+                      (eqv? #\= (string-ref src src-offset)))
+                 ;; done
+                 (let ((dst-len (base64-decode-finish dst dst-len b1 b2 b3)))
+                   (write-string dst dst-len out)))
+                ((eqv? b1 *outside-char*)
+                 (write-string dst dst-len out)
+                 (lp 0))
+                (else
+                 (write-string dst dst-len out)
+                 ;; one to three chars left in buffer
+                 (string-set! src 0 (enc b1))
+                 (cond
+                  ((eqv? b2 *outside-char*)
+                   (lp 1))
+                  (else
+                   (string-set! src 1 (enc b2))
+                   (cond
+                    ((eqv? b3 *outside-char*)
+                     (lp 2))
+                    (else
+                     (string-set! src 2 (enc b3))
+                     (lp 3))))))))))
+           (else
+            ;; end of source - just decode and write once
+            (base64-decode-string!
+             src 0 src-len dst
+             (lambda (src-offset dst-len b1 b2 b3)
+               (let ((dst-len (base64-decode-finish dst dst-len b1 b2 b3)))
+                 (write-string dst dst-len out)))))))))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; encoding
+
+(define (base64-encode-string str)
+  (let* ((len (string-length str))
+         (quot (quotient len 3))
+         (rem (- len (* quot 3)))
+         (res-len (arithmetic-shift (+ quot (if (zero? rem) 0 1)) 2))
+         (res (make-string res-len)))
+    (base64-encode-string! str 0 len res)
+    res))
+
+(define (base64-encode-string! str start end res)
+  (let* ((res-len (string-length res))
+         (limit (- end 2)))
+    (let lp ((i start) (j 0))
+      (if (>= i limit)
+          (case (- end i)
+            ((1)
+             (let ((b1 (char->integer (string-ref str i))))
+               (string-set! res j (enc (arithmetic-shift b1 -2)))
+               (string-set! res
+                            (+ j 1)
+                            (enc (arithmetic-shift (bitwise-and #b11 b1) 4)))
+               (string-set! res (+ j 2) #\=)
+               (string-set! res (+ j 3) #\=)))
+            ((2)
+             (let ((b1 (char->integer (string-ref str i)))
+                   (b2 (char->integer (string-ref str (+ i 1)))))
+               (string-set! res j (enc (arithmetic-shift b1 -2)))
+               (string-set! res
+                            (+ j 1)
+                            (enc (bitwise-ior
+                                  (arithmetic-shift (bitwise-and #b11 b1) 4)
+                                  (extract-bit-field 4 4 b2))))
+               (string-set! res
+                            (+ j 2)
+                            (enc (arithmetic-shift (extract-bit-field 4 0 b2)
+                                                   2)))
+               (string-set! res (+ j 3) #\=))))
+          (let ((b1 (char->integer (string-ref str i)))
+                (b2 (char->integer (string-ref str (+ i 1))))
+                (b3 (char->integer (string-ref str (+ i 2)))))
+            (string-set! res j (enc (arithmetic-shift b1 -2)))
+            (string-set! res
+                         (+ j 1)
+                         (enc (bitwise-ior
+                               (arithmetic-shift (bitwise-and #b11 b1) 4)
+                               (extract-bit-field 4 4 b2))))
+            (string-set! res
+                         (+ j 2)
+                         (enc (bitwise-ior
+                               (arithmetic-shift (extract-bit-field 4 0 b2) 2)
+                               (extract-bit-field 2 6 b3))))
+            (string-set! res (+ j 3) (enc (bitwise-and #b111111 b3)))
+            (lp (+ i 3) (+ j 4)))))))
+
+(define (base64-encode . o)
+  (let ((in (if (pair? o) (car o) (current-input-port)))
+        (out (if (and (pair? o) (pair? (cdr o)))
+                 (cadr o)
+                 (current-output-port))))
+    (let ((src (make-string encode-src-length))
+          (dst (make-string
+                (arithmetic-shift (quotient encode-src-length 3) 2))))
+      (let lp ()
+        (let ((n (read-string! 2048 src in)))
+          (base64-encode-string! src 0 n dst)
+          (write-string dst (* 3 (quotient (+ n 3) 4)) out)
+          (if (= n 2048)
+              (lp)))))))
+
+(define (base64-encode-header encoding str . o)
+  (define (round4 i) (arithmetic-shift (arithmetic-shift i -2) 2))
+  (let ((start-col (if (pair? o) (car o) 0))
+        (max-col (if (and (pair? o) (pair? (cdr o)))
+                     (car (cdr o))
+                     *default-max-col*))
+        (nl (if (and (pair? o) (pair? (cdr o)) (pair? (cdr (cdr o))))
+                (car (cdr (cdr o)))
+                "\r\n")))
+    (let* ((prefix (string-append "=?" encoding "?B?"))
+           (prefix-length (+ 2 (string-length prefix)))
+           (effective-max-col (round4 (- max-col prefix-length)))
+           (first-max-col (round4 (- effective-max-col start-col)))
+           (str (base64-encode-string str))
+           (len (string-length str)))
+      (if (<= len first-max-col)
+          (string-append prefix str "?=")
+          (string-append
+           (if (positive? first-max-col)
+               (string-append
+                prefix (substring str 0 first-max-col) "?=" nl "\t" prefix)
+               "")
+           (string-concatenate (string-chop (substring str first-max-col len)
+                                            effective-max-col)
+                               (string-append "?=" nl "\t" prefix))
+           "?=")))))
+
diff --git a/lib/chibi/mime.module b/lib/chibi/mime.module
new file mode 100644
index 00000000..2c10dbd1
--- /dev/null
+++ b/lib/chibi/mime.module
@@ -0,0 +1,7 @@
+
+(define-module (chibi mime)
+  (export mime-ref assoc-ref mime-header-fold mime-headers->list
+          mime-parse-content-type mime-decode-header
+          mime-message-fold mime-message->sxml)
+  (import-immutable (scheme) (chibi base64) (chibi quoted-printable) (chibi io))
+  (include "mime.scm"))
diff --git a/lib/chibi/mime.scm b/lib/chibi/mime.scm
new file mode 100644
index 00000000..e712d7fa
--- /dev/null
+++ b/lib/chibi/mime.scm
@@ -0,0 +1,410 @@
+;; mime.scm -- RFC2045 MIME library
+;; Copyright (c) 2005-2009 Alex Shinn.  All rights reserved.
+;; BSD-style license: http://synthcode.com/license.txt
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; RFC2822 headers
+
+;; Procedure: mime-header-fold kons knil [source [limit [kons-from]]]
+;;
+;;  Performs a fold operation on the MIME headers of source which can be
+;;  either a string or port, and defaults to current-input-port.  kons
+;;  is called on the three values:
+;;     kons header value accumulator
+;;  where accumulator begins with knil.  Neither the header nor the
+;;  value are modified, except wrapped lines are handled for the value.
+;;
+;;  The optional procedure KONS-FROM is a procedure to be called when
+;;  the first line of the headers is an "From <address> <date>" line, to
+;;  enable this procedure to be used as-is on mbox files and the like.
+;;  It defaults to KONS, and if such a line is found the fold will begin
+;;  with (KONS-FROM "%from" <address> (KONS-FROM "%date" <date> KNIL)).
+;;
+;; The optional LIMIT gives a limit on the number of headers to read.
+
+;; Procedure: mime-headers->list [source]
+;;   Return an alist of the MIME headers from source with headers all
+;;   downcased.
+
+;; Procedure: mime-parse-content-type str
+;;   Parses STR as a Content-Type style-value returning the list
+;;     (type (attr . val) ...)
+;;  For example:
+;;     (mime-parse-content-type
+;;        "text/html; CHARSET=US-ASCII; filename=index.html")
+;;       => ("text/html" ("charset" . "US-ASCII") ("filename" . "index.html"))
+
+;; Procedure: mime-decode-header str
+;;   Replace all occurrences of RFC1522 =?ENC?...?= escapes in STR with
+;;   the appropriate decoded and charset converted value.
+
+;; Procedure: mime-ref headers str [default]
+;;   A case-insensitive assoc-ref.
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; RFC2045 MIME encoding
+
+;; Procedure: mime-message-fold src headers kons knil
+;;   Performs a fold operation on the given string or port SRC as a MIME
+;;   body corresponding to the headers give in HEADERS.  KONS is called
+;;   on the successive values:
+;;
+;;      KONS part-headers part-body accumulator
+;;
+;;   where part-headers are the headers for the given MIME part (the
+;;   original headers for single-part MIME), part-body is the
+;;   appropriately decoded and charset-converted body of the message,
+;;   and the accumulator begins with KNIL.
+;;
+;; TODO: Extend mime-message-fold to (optionally?) pass KONS an
+;; input-port instead of string for the body to handle very large bodies
+;; (this is not much of an issue for SMTP since the messages are in
+;; practice limited, but it could be problematic for large HTTP bodies).
+;;
+;; This does a depth-first search, folding in sequence.  It should
+;; probably be doing a tree-fold as in html-parser.
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(define mime-line-length-limit 4096)
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; association lists
+
+(define (assoc* key ls . o)
+  (let ((eq (if (pair? o) (car o) equal?)))
+    (let lp ((ls ls))
+      (cond
+        ((null? ls) #f)
+        ((eq key (caar ls)) (car ls))
+        (else (lp (cdr ls)))))))
+
+(define (assoc-ref ls key . o)
+  (let ((default (and (pair? o) (car o)))
+        (eq (if (and (pair? o) (pair? (cdr o))) (car (cdr o)) equal?)))
+    (cond ((assoc* key ls eq) => cdr)
+          (else default))))
+
+(define (mime-ref ls key . o)
+  (assoc-ref ls key (and (pair? o) (car o)) string-ci=?))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; simple matching instead of regexps
+
+(define (match-mbox-from-line line)
+  (let ((len (string-length line)))
+    (and (> len 5)
+         (string=? (substring line 0 5) "From ")
+         (let lp ((i 6))
+           (cond
+             ((= i len) (list (substring line 5 len) ""))
+             ((memq (string-ref line i) '(#\space #\tab))
+              (list (substring line 5 i) (substring line (+ i 1) len)))
+             (else (lp (+ i 1))))))))
+
+(define (string-scan-colon-or-maybe-equal str)
+  (let ((len (string-length str)))
+    (let lp ((i 0) (best #f))
+      (if (= i len)
+          best
+          (let ((c (string-ref str i)))
+            (cond ((or (char-alphabetic? c)
+                       (char-numeric? c)
+                       (memv c '(#\- #\_)))
+                   (lp (+ i 1) best))
+                  ((eq? c #\:)
+                   (if (= i 0) #f i))
+                  ((eqv? c #\=)
+                   (lp (+ i 1) (or best i)))
+                  (else
+                   best)))))))
+
+(define (string-skip-white-space str i)
+  (let ((lim (string-length str)))
+    (let lp ((i i))
+      (cond ((>= i lim) lim)
+            ((char-whitespace? (string-ref str i)) (lp (+ i 1)))
+            (else i)))))
+
+(define (match-mime-header-line line)
+  (let ((i (string-scan-colon-or-maybe-equal line)))
+    (and i
+         (let ((j (string-skip-white-space line (+ i 1))))
+           (list (substring line 0 i)
+                 (substring line j (string-length line)))))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; dummy encoder
+
+(define (ces-convert str . x)
+  str)
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; some srfi-13 & string utils
+
+(define (string-copy! to tstart from . o)
+  (let ((start (if (pair? o) (car o) 0))
+        (end (if (and (pair? o) (pair? (cdr o))) (cadr o) (string-length from))))
+    (let lp ((i start) (j tstart))
+      (cond
+       ((< i end)
+        (string-set! to j (string-ref from i))
+        (lp (+ i 1) (+ j 1)))))))
+
+(define (string-concatenate-reverse ls)
+  (let lp ((ls ls) (rev '()) (len 0))
+    (if (null? ls)
+        (let ((res (make-string len)))
+          (let lp ((ls rev) (i 0))
+            (cond
+             ((null? ls)
+              res)
+             (else
+              (string-copy! res i (car ls))
+              (lp (cdr ls) (+ i (string-length (car ls))))))))
+        (lp (cdr ls) (cons (car ls) rev) (+ len (string-length (car ls)))))))
+
+(define (string-downcase s . o)
+  (let ((start (if (pair? o) (car o) 0))
+        (end (if (and (pair? o) (pair? (cdr o))) (cadr o) (string-length s))))
+    (let* ((len (- end start)) (s2 (make-string len)))
+      (let lp ((i start) (j 0))
+        (cond
+         ((>= i end)
+          s2)
+         (else
+          (string-set! s2 j (char-downcase (string-ref s i)))
+          (lp (+ i 1) (+ j 1))))))))
+
+(define (string-char-index str c . o)
+  (let ((start (if (pair? o) (car o) 0))
+        (end (if (and (pair? o) (pair? (cdr o))) (cadr o) (string-length str))))
+    (let lp ((i start))
+      (cond
+       ((= i end) #f)
+       ((eq? c (string-ref str i)) i)
+       (else (lp (+ i 1)))))))
+
+(define (string-trim-white-space s)
+  (let ((len (string-length s)))
+    (let lp ((i 0))
+      (cond ((= i len) "")
+            ((char-whitespace? (string-ref s i)) (lp (+ i 1)))
+            (else
+             (let lp ((j (- len 1)))
+               (cond ((<= j i) "")
+                     ((char-whitespace? (string-ref s j)) (lp (- j 1)))
+                     (else (substring s i (+ j 1))))))))))
+
+(define (string-split str ch)
+  (let ((len (string-length str)))
+    (let lp ((i 0) (res '()))
+      (let ((j (string-char-index str ch i)))
+        (if j
+            (lp (+ j 1) (cons (substring str i j) res))
+            (reverse (cons (substring str i len) res)))))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; header parsing
+
+(define (mime-header-fold kons knil . o)
+  (let ((src (and (pair? o) (car o)))
+        (limit (and (pair? o) (pair? (cdr o)) (car (cdr o))))
+        (kons-from (if (and (pair? o) (pair? (cdr o)) (pair? (cddr o))) (caddr o) kons)))
+    ((if (string? src) mime-header-fold-string mime-header-fold-port)
+     kons knil (or src (current-input-port)) limit kons-from)))
+
+(define (mime-header-fold-string kons knil str limit kons-from)
+  (call-with-input-string str
+    (lambda (in) (mime-header-fold-port kons knil in limit kons-from))))
+
+(define (mime-header-fold-port kons knil port limit kons-from)
+  (define (out line acc count)
+    (cond
+     ((or (and limit (> count limit)) (eof-object? line) (string=? line ""))
+      acc)
+     ((match-mime-header-line line)
+      => (lambda (m) (in (car m) (list (cadr m)) acc (+ count 1))))
+     (else
+      ;;(warn "invalid header line: ~S\n" line)
+      (out (read-line port mime-line-length-limit) acc (+ count 1)))))
+  (define (in header value acc count)
+    (let ((line (read-line port mime-line-length-limit)))
+      (cond
+       ((and limit (> count limit))
+        acc)
+       ((or (eof-object? line) (string=? line ""))
+        (kons header (string-concatenate-reverse value) acc))
+       ((char-whitespace? (string-ref line 0))
+        (in header (cons line value) acc (+ count 1)))
+       (else
+        (out line
+             (kons header (string-concatenate-reverse value) acc)
+             (+ count 1))))))
+  (let ((first-line (read-line port mime-line-length-limit)))
+    (cond
+     ((eof-object? first-line)
+      knil)
+     ((and kons-from (match-mbox-from-line first-line))
+      => (lambda (m) ; special case check on first line for mbox files
+           (out (read-line port mime-line-length-limit)
+                (kons-from "%from" (car m)
+                           (kons-from "%date" (cadr m) knil))
+                0)))
+     (else
+      (out first-line knil 0)))))
+
+(define (mime-headers->list . o)
+  (reverse
+   (apply
+    mime-header-fold
+    (lambda (h v acc) (cons (cons (string-downcase h) v) acc))
+    '()
+    o)))
+
+(define (mime-split-name+value s)
+  (let ((i (string-char-index s #\=)))
+    (if i
+      (cons (string-downcase (string-trim-white-space (substring s 0 i)))
+            (if (= i (string-length s))
+              ""
+              (if (eqv? #\" (string-ref s (+ i 1)))
+                (substring s (+ i 2) (- (string-length s) 1))
+                (substring s (+ i 1) (string-length s)))))
+      (cons (string-downcase (string-trim-white-space s)) ""))))
+
+(define (mime-parse-content-type str)
+  (map mime-split-name+value (string-split str #\;)))
+
+(define (mime-decode-header str)
+  (let* ((len (string-length str))
+         (limit (- len 8))) ; need at least 8 chars: "=?Q?X??="
+    (let lp ((i 0) (from 0) (res '()))
+      (if (>= i limit)
+        (string-concatenate (reverse (cons (substring str from len) res)))
+        (if (and (eqv? #\= (string-ref str i))
+                 (eqv? #\? (string-ref str (+ i 1))))
+          (let* ((j (string-char-index str #\? (+ i 3)))
+                 (k (string-char-index str #\? (+ j 3))))
+            (if (and j k (< (+ k 1) len)
+                     (eqv? #\? (string-ref str (+ j 2)))
+                     (memq (string-ref str (+ j 1)) '(#\Q #\B #\q #\b))
+                     (eqv? #\= (string-ref str (+ k 1))))
+              (let ((decode (if (memq (string-ref str (+ j 1)) '(#\Q #\q))
+                               quoted-printable-decode-string
+                               base64-decode-string))
+                    (cset (substring str (+ i 2) j))
+                    (content (substring str (+ j 3) k))
+                    (k2 (+ k 2)))
+                (lp k2 k2 (cons (ces-convert (decode content) cset)
+                                (cons (substring str from i) res))))
+              (lp (+ i 2) from res)))
+          (lp (+ i 1) from res))))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; message parsing
+
+(define (mime-read-to-boundary port boundary next final)
+  (let ((final-boundary (and boundary (string-append boundary "--"))))
+    (let lp ((res '()))
+      (let ((line (read-line port mime-line-length-limit)))
+        (cond
+         ((or (eof-object? line) (equal? line final-boundary))
+          (final (string-concatenate (reverse res)
+                                     (call-with-output-string newline))))
+         ((equal? line boundary)
+          (next (string-concatenate (reverse res)
+                                    (call-with-output-string newline))))
+         (else
+          (lp (cons line res))))))))
+
+(define (mime-convert-part str cte enc)
+  (let ((str (cond
+              ((and (string? cte) (string-ci=? cte "quoted-printable"))
+               (quoted-printable-decode-string str))
+              ((and (string? cte) (string-ci=? cte "base64"))
+               (base64-decode-string str))
+              (else
+               str))))
+    (if (string? enc) (ces-convert str enc) str)))
+
+(define (mime-read-part port cte enc boundary next final)
+  (mime-read-to-boundary
+   port boundary
+   (lambda (x) (next (mime-convert-part x cte enc)))
+   (lambda (x) (final (mime-convert-part x cte enc)))))
+
+;; (kons parent-headers part-headers part-body seed)
+;; (start headers seed)
+;; (end headers parent-seed seed)
+(define (mime-message-fold src kons init-seed . o)
+  (let ((port (if (string? src) (open-input-string src) src)))
+    (let ((kons-start
+           (if (pair? o) (car o) (lambda (headers seed) '())))
+          (kons-end
+           (if (and (pair? o) (pair? (cdr o)))
+               (car (cdr o))
+               (lambda (headers parent-seed seed)
+                 `((mime (^ ,@headers)
+                         ,@(if (pair? seed) (reverse seed) seed))
+                   ,@parent-seed))))
+          (headers
+           (if (and (pair? o) (pair? (cdr o)) (pair? (cdr (cdr o))))
+               (car (cdr (cdr o)))
+               (mime-headers->list port))))
+      (let tfold ((parent-headers '())
+                  (headers headers)
+                  (seed init-seed)
+                  (boundary #f)
+                  (next (lambda (x) x))
+                  (final (lambda (x) x)))
+        (let* ((ctype (mime-parse-content-type
+                       (mime-ref headers "Content-Type" "text/plain")))
+               (type (string-trim-white-space (caar ctype)))
+               (enc (string-trim-white-space
+                     (or (mime-ref ctype "charset")
+                         (mime-ref headers "charset" "ASCII"))))
+               (cte (string-trim-white-space
+                     (or (mime-ref headers "Content-Transfer-Encoding")
+                         (mime-ref headers "Encoding" "7-bit")))))
+          (cond
+           ((and (string-ci=? type "multipart/")
+                 (mime-ref ctype "boundary"))
+            => (lambda (boundary2)
+                 (let ((boundary2 (string-append "--" boundary2)))
+                   ;; skip preamble
+                   (mime-read-to-boundary port boundary2 (lambda (x) x) (lambda (x) x))
+                   (let lp ((part-seed (kons-start headers seed)))
+                     (let ((part-headers (mime-headers->list port)))
+                       (tfold parent-headers part-headers
+                              part-seed boundary2
+                              lp
+                              (lambda (x)
+                                ;; skip epilogue
+                                (if boundary
+                                    (mime-read-to-boundary port boundary
+                                                           (lambda (x) x) (lambda (x) x)))
+                                (next (kons-end headers seed x)))
+                              ))))))
+           (else
+            (mime-read-part
+             port cte enc boundary
+             (lambda (x) (next (kons parent-headers headers x seed)))
+             (lambda (x) (final (kons parent-headers headers x seed)))))))))))
+
+;; (mime (^ (header . value) ...) parts ...)
+(define (mime-message->sxml . o)
+  (car
+   (apply
+    mime-message-fold
+    (if (pair? o) (car o) (current-input-port))
+    (lambda (parent-headers headers body seed)
+      `((mime (^ ,@headers) ,body) ,@seed))
+    '()
+    (lambda (headers seed) '())
+    (lambda (headers parent-seed seed)
+      `((mime (^ ,@headers)
+              ,@(if (pair? seed) (reverse seed) seed))
+        ,@parent-seed))
+    (if (pair? o) (cdr o) '()))))
+
diff --git a/lib/chibi/net.module b/lib/chibi/net.module
index 41cdafe4..845a7aa8 100644
--- a/lib/chibi/net.module
+++ b/lib/chibi/net.module
@@ -1,6 +1,7 @@
 
 (define-module (chibi net)
-  (export sockaddr? address-info? get-address-info socket connect with-net-io
+  (export sockaddr? address-info? get-address-info socket connect
+          with-net-io open-net-io
           address-info-family address-info-socket-type address-info-protocol
           address-info-address address-info-address-length address-info-next)
   (import-immutable (scheme))
diff --git a/lib/chibi/net.scm b/lib/chibi/net.scm
index 85ed756a..5f912cb5 100644
--- a/lib/chibi/net.scm
+++ b/lib/chibi/net.scm
@@ -1,9 +1,13 @@
 ;; net.scm -- the high-level network interface
-;; Copyright (c) 2009 Alex Shinn.  All rights reserved.
+;; Copyright (c) 2010 Alex Shinn.  All rights reserved.
 ;; BSD-style license: http://synthcode.com/license.txt
 
-(define (with-net-io host service proc)
-  (let lp ((addr (get-address-info host service #f)))
+(define (open-net-io host service)
+  (let lp ((addr (get-address-info host
+                                   (if (integer? service)
+                                       (number->string service)
+                                       service)
+                                   #f)))
     (if (not addr)
         (error "couldn't find address" host service)
         (let ((sock (socket (address-info-family addr)
@@ -16,8 +20,13 @@
                             (address-info-address addr)
                             (address-info-address-length addr)))
                   (lp (address-info-next addr))
-                  (let ((in (open-input-file-descriptor sock))
-                        (out (open-output-file-descriptor sock)))
-                    (let ((res (proc in out)))
-                      (close-input-port in)
-                      res))))))))
+                  (list (open-input-file-descriptor sock)
+                        (open-output-file-descriptor sock))))))))
+
+(define (with-net-io host service proc)
+  (let ((io (open-net-io host service)))
+    (if (not (pair? io))
+        (error "couldn't find address" host service)
+        (let ((res (proc (car io) (car (cdr io)))))
+          (close-input-port (car io))
+          res))))
diff --git a/lib/chibi/net/http.module b/lib/chibi/net/http.module
new file mode 100644
index 00000000..352bf7b4
--- /dev/null
+++ b/lib/chibi/net/http.module
@@ -0,0 +1,7 @@
+
+(define-module (chibi net http)
+  (export http-get call-with-input-url with-input-from-url
+          http-parse-request http-parse-form)
+  (import-immutable (scheme) (srfi 39) (chibi net) (chibi io)
+                    (chibi uri) (chibi mime))
+  (include "http.scm"))
diff --git a/lib/chibi/net/http.scm b/lib/chibi/net/http.scm
new file mode 100644
index 00000000..37cac5e6
--- /dev/null
+++ b/lib/chibi/net/http.scm
@@ -0,0 +1,180 @@
+;; http.scm -- http client
+;; Copyright (c) 2009 Alex Shinn.  All rights reserved.
+;; BSD-style license: http://synthcode.com/license.txt
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; string utils
+
+(define (string-char-index str c . o)
+  (let ((start (if (pair? o) (car o) 0))
+        (end (if (and (pair? o) (pair? (cdr o))) (cadr o) (string-length str))))
+    (let lp ((i start))
+      (cond
+       ((= i end) #f)
+       ((eq? c (string-ref str i)) i)
+       (else (lp (+ i 1)))))))
+
+(define (string-split str ch)
+  (let ((len (string-length str)))
+    (let lp ((i 0) (res '()))
+      (let ((j (string-char-index str ch i)))
+        (if j
+            (lp (+ j 1) (cons (substring str i j) res))
+            (reverse (cons (substring str i len) res)))))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; client utils
+
+(define http-user-agent "chibi")
+
+(define http-redirect-limit 10)
+(define http-chunked-buffer-size 4096)
+(define http-chunked-size-limit 409600)
+
+(define (string-scan str ch . o)
+  (let ((start (if (pair? o) (car o) 0))
+        (end (if (and (pair? o) (pair? (cdr o))) (cadr o) (string-length str))))
+    (let lp ((i start))
+      (and (< i end)
+           (if (eqv? ch (string-ref str i))
+               i
+               (lp (+ i 1)))))))
+
+(define (http-parse-response line)
+  (let* ((len (string-length line))
+         (i (or (string-scan line #\space 0 len) len))
+         (j (or (string-scan line #\space (+ i 1) len) len))
+         (n (and (< i j) (string->number (substring line (+ i 1) j)))))
+    (if (not (integer? n))
+        (error "bad response" line i j)
+        (list (substring line 0 i)
+              n
+              (if (>= j len) "" (substring line (+ j 1) len))))))
+
+(define (http-wrap-chunked-input-port in)
+  (define (read-chunk in)
+    (let* ((line (read-line in))
+           (n (and (string? line) (string->number line 16))))
+      (display "read-chunk ") (write line) (newline)
+      (cond
+       ((not (and (integer? n) (<= 0 n http-chunked-size-limit)))
+        (error "invalid chunked size line" line))
+       ((zero? n) "")
+       (else (read-string n in)))))
+  (make-generated-input-port
+   (lambda () (read-chunk in))))
+
+(define (http-get/raw url in-headers limit)
+  (if (<= limit 0)
+      (error "http-get: redirect limit reached" url)
+      (let* ((uri (if (uri? url) url (string->uri url)))
+             (host (and uri (uri-host uri))))
+        (if (not host)
+            (error "invalid url" url)
+            (let* ((io (open-net-io
+                        host
+                        (or (uri-port uri)
+                            (if (eq? 'https (uri-scheme uri)) 443 80))))
+                   (in (car io))
+                   (out (car (cdr io))))
+              (display "GET " out)
+              (display (or (uri-path uri) "/") out)
+              (display " HTTP/1.0\r\n" out)
+              (display "Host: " out) (display host out) (display "\r\n" out)
+              (cond
+               ((not (mime-ref in-headers "user-agent"))
+                (display "User-Agent: " out)
+                (display http-user-agent out)
+                (display "\r\n" out)))
+              (for-each
+               (lambda (x)
+                 (display (car x) out)  (display ": " out)
+                 (display (cdr x) out) (display "\r\n" out))
+               in-headers)
+              (display "Connection: close\r\n\r\n" out)
+              (flush-output out)
+              (let* ((resp (http-parse-response (read-line in)))
+                     (headers (mime-headers->list in))
+                     (status (quotient (cadr resp) 100)))
+                (case status
+                  ((2)
+                   (let ((enc (mime-ref headers "transfer-encoding")))
+                     (cond
+                      ((equal? enc "chunked")
+                       (http-wrap-chunked-input-port in))
+                      (else
+                       in))))
+                  ((3)
+                   (close-input-port in)
+                   (close-output-port out)
+                   (let ((url2 (mime-ref headers "location")))
+                     (if url2
+                         (http-get/raw url2 in-headers (- limit 1))
+                         (error "redirect with no location header"))))
+                  (else
+                   (close-input-port in)
+                   (close-output-port out)
+                   (error "couldn't retrieve url" url resp)))))))))
+
+(define (http-get url . headers)
+  (http-get/raw url
+                (if (pair? headers) (car headers) '())
+                http-redirect-limit))
+
+(define (call-with-input-url url proc)
+  (let* ((p (http-get url))
+         (res (proc p)))
+    (close-input-port p)
+    res))
+
+(define (with-input-from-url url thunk)
+  (let ((p (http-get url)))
+    (let ((res (parameterize ((current-input-port p)) (thunk))))
+      (close-input-port p)
+      res)))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; server utils
+
+;; read and parse a request line
+(define (http-parse-request . o)
+  (let ((line (string-split
+               (read-line (if (pair? o) (car o) (current-input-port)) 4096))))
+    (cons (string->symbol (car line)) (cdr line))))
+
+;; Parse a form body with a given URI and MIME headers (as parsed with
+;; mime-headers->list).  Returns an alist of (name . value) for every
+;; query or form parameter.
+(define (http-parse-form uri headers . o)
+  (let* ((in (if (pair? o) (car o) (current-input-port)))
+         (type (mime-ref headers
+                         "content-type"
+                         "application/x-www-form-urlencoded")) 
+         (query0 (or (uri-query (if (string? uri) (string->uri uri) uri)) '()))
+         (query (if (string? query0) (uri-query->alist query0) query0)))
+    (cond
+     ((string-ci=? "multipart/" type)
+      (let ((mime (mime-message->sxml in headers)))
+        (append
+         (let lp ((ls (cddr mime))
+                  (res '()))
+           (cond
+            ((null? ls)
+             res)
+            ((and (pair? (car ls))
+                  (eq? 'mime (caar ls))
+                  (pair? (cdar ls))
+                  (pair? (cadar ls))
+                  (memq (caadar ls) '(^ @)))
+             (let* ((disp0 (mime-ref (cdadar ls) "content-disposition" ""))
+                    (disp (mime-parse-content-type disp0))
+                    (name (mime-ref disp "name")))
+               (if name
+                   (lp (cdr ls) (cons (cons name (caddar ls)) res))
+                   (lp (cdr ls) res))))
+            (else
+             (lp (cdr ls) res))))
+         query)))
+     (else
+      query))))
+
diff --git a/lib/chibi/quoted-printable.module b/lib/chibi/quoted-printable.module
new file mode 100644
index 00000000..9cbec430
--- /dev/null
+++ b/lib/chibi/quoted-printable.module
@@ -0,0 +1,7 @@
+
+(define-module (chibi quoted-printable)
+  (export quoted-printable-encode quoted-printable-encode-string
+          quoted-printable-encode-header
+          quoted-printable-decode quoted-printable-decode-string)
+  (import-immutable (scheme) (srfi 33) (chibi io))
+  (include "quoted-printable.scm"))
diff --git a/lib/chibi/quoted-printable.scm b/lib/chibi/quoted-printable.scm
new file mode 100644
index 00000000..80709026
--- /dev/null
+++ b/lib/chibi/quoted-printable.scm
@@ -0,0 +1,157 @@
+;; quoted-printable.scm -- RFC2045 implementation
+;; Copyright (c) 2005-2009 Alex Shinn.  All rights reserved.
+;; BSD-style license: http://synthcode.com/license.txt
+
+;; Procedure: quoted-printable-encode-string str [start-col max-col]
+;;   Return a quoted-printable encoded representation of string
+;;   according to the official standard as described in RFC2045.
+;;
+;;   ? and _ are always encoded for compatibility with RFC1522 encoding,
+;;   and soft newlines are inserted as necessary to keep each lines
+;;   length less than MAX-COL (default 76).  The starting column may be
+;;   overridden with START-COL (default 0).
+
+;; Procedure: quoted-printable-decode-string str [mime?]
+;;   Return a quoted-printable decoded representation of string.  If
+;;   MIME? is specified and true, _ will be decoded as as space in
+;;   accordance with RFC1522.  No errors will be raised on invalid
+;;   input.
+
+;; Procedure: quoted-printable-encode [port start-col max-col]
+;; Procedure: quoted-printable-decode [port start-col max-col]
+;;   Variations of the above which read and write to ports.
+
+;; Procedure: quoted-printable-encode-header enc str [start-col max-col]
+;;   Return a quoted-printable encoded representation of string as
+;;   above, wrapped in =?ENC?Q?...?= as per RFC1522, split across
+;;   multiple MIME-header lines as needed to keep each lines length less
+;;   than MAX-COL.  The string is encoded as is, and the encoding ENC is
+;;   just used for the prefix, i.e. you are responsible for ensuring STR
+;;   is already encoded according to ENC.
+
+;; Example:
+
+;; (define (mime-encode-header header value charset)
+;;   (let ((prefix (string-append header ": "))
+;;         (str (ces-convert value "UTF8" charset)))
+;;     (string-append
+;;      prefix
+;;      (quoted-printable-encode-header charset str (string-length prefix)))))
+
+;; This API is backwards compatible with the Gauche library
+;; rfc.quoted-printable.
+
+(define *default-max-col* 76)
+
+;; Allow for RFC1522 quoting for headers by always escaping ? and _
+(define (qp-encode str start-col max-col separator)
+  (define (hex i) (integer->char (+ i (if (<= i 9) 48 55))))
+  (let ((end (string-length str))
+        (buf (make-string max-col)))
+    (let lp ((i 0) (col start-col) (res '()))
+      (cond
+        ((= i end)
+         (if (pair? res)
+           (string-concatenate (reverse (cons (substring buf 0 col) res))
+                               separator)
+           (substring buf start-col col)))
+        ((>= col (- max-col 3))
+         (lp i 0 (cons (substring buf (if (pair? res) 0 start-col) col) res)))
+        (else
+         (let ((c (char->integer (string-ref str i))))
+           (cond
+             ((and (<= 33 c 126) (not (memq c '(61 63 95))))
+              (string-set! buf col (integer->char c))
+              (lp (+ i 1) (+ col 1) res))
+             (else
+              (string-set! buf col #\=)
+              (string-set! buf (+ col 1) (hex (arithmetic-shift c -4)))
+              (string-set! buf (+ col 2) (hex (bitwise-and c #b1111)))
+              (lp (+ i 1) (+ col 3) res)))))))))
+
+(define (quoted-printable-encode-string . o)
+  (let ((src (if (pair? o) (car o) (current-input-port)))
+        (start-col (if (and (pair? o) (pair? (cdr o))) (cadr o) 0))
+        (max-col (if (and (pair? o) (pair? (cdr o)) (pair? (cddr o)))
+                     (caddr o)
+                     *default-max-col*)))
+    (qp-encode (if (string? src) src (read-string #f src))
+               start-col max-col "=\r\n")))
+
+(define (quoted-printable-encode . o)
+  (display (apply (quoted-printable-encode-string o))))
+
+(define (quoted-printable-encode-header encoding . o)
+  (let ((src (if (pair? o) (car o) (current-input-port)))
+        (start-col (if (and (pair? o) (pair? (cdr o))) (cadr o) 0))
+        (max-col (if (and (pair? o) (pair? (cdr o)) (pair? (cddr o)))
+                     (caddr o)
+                     *default-max-col*))
+        (nl (if (and (pair? o) (pair? (cdr o)) (pair? (cddr o)) (pair? (cdddr o)))
+                (cadddr o)
+                "\r\n")))
+    (let* ((prefix (string-append "=?" encoding "?Q?"))
+           (prefix-length (+ 2 (string-length prefix)))
+           (separator (string-append "?=" nl "\t" prefix))
+           (effective-max-col (- max-col prefix-length)))
+      (string-append prefix
+                     (qp-encode (if (string? src) src (read-string #f src))
+                                start-col effective-max-col separator)
+                     "?="))))
+
+(define (quoted-printable-decode-string  . o)
+  (define (hex? c) (or (char-numeric? c) (<= 65 (char->integer c) 70)))
+  (define (unhex1 c)
+    (let ((i (char->integer c))) (if (>= i 65) (- i 55) (- i 48))))
+  (define (unhex c1 c2)
+    (integer->char (+ (arithmetic-shift (unhex1 c1) 4) (unhex1 c2))))
+  (let ((src (if (pair? o) (car o) (current-input-port)))
+        (mime-header? (and (pair? o) (pair? (cdr o)) (car (cdr o)))))
+    (let* ((str (if (string? src) src (read-string #f src)))
+           (end (string-length str)))
+      (call-with-output-string
+        (lambda (out)
+          (let lp ((i 0))
+            (cond
+             ((< i end)
+              (let ((c (string-ref str i)))
+                (case c
+                  ((#\=)                ; = escapes
+                   (cond
+                    ((< (+ i 2) end)
+                     (let ((c2 (string-ref str (+ i 1))))
+                       (cond
+                        ((eq? c2 #\newline) (lp (+ i 2)))
+                        ((eq? c2 #\return)
+                         (lp (if (eq? (string-ref str (+ i 2)) #\newline)
+                                 (+ i 3)
+                                 (+ i 2))))
+                        ((hex? c2)
+                         (let ((c3 (string-ref str (+ i 2))))
+                           (if (hex? c3) (write-char (unhex c2 c3) out))
+                           (lp (+ i 3))))
+                        (else (lp (+ i 3))))))))
+                  ((#\_)                ; maybe translate _ to space
+                   (write-char (if mime-header? #\space c) out)
+                   (lp (+ i 1)))
+                  ((#\space #\tab)      ; strip trailing whitespace
+                   (let lp2 ((j (+ i 1)))
+                     (cond
+                      ((not (= j end))
+                       (case (string-ref str j)
+                         ((#\space #\tab) (lp2 (+ j 1)))
+                         ((#\newline)
+                          (lp (+ j 1)))
+                         ((#\return)
+                          (let ((k (+ j 1)))
+                            (lp (if (and (< k end)
+                                         (eqv? #\newline (string-ref str k)))
+                                    (+ k 1) k))))
+                         (else (display (substring str i j) out) (lp j)))))))
+                  (else                 ; a literal char
+                   (write-char c out)
+                   (lp (+ i 1)))))))))))))
+
+(define (quoted-printable-decode . o)
+  (display (apply quoted-printable-decode-string o)))
+
diff --git a/lib/chibi/uri.module b/lib/chibi/uri.module
index 2456dd9f..46f9e6a6 100644
--- a/lib/chibi/uri.module
+++ b/lib/chibi/uri.module
@@ -1,7 +1,7 @@
 
 (define-module (chibi uri)
-  (export uri->string make-uri string->uri
-          uri-scheme uri-user uri-host uri-path uri-query uri-fragment
+  (export uri? uri->string make-uri string->uri
+          uri-scheme uri-user uri-host uri-port uri-path uri-query uri-fragment
           uri-with-scheme uri-with-user uri-with-host uri-with-path
           uri-with-query uri-with-fragment
           uri-encode uri-decode uri-query->alist uri-alist->query)
diff --git a/lib/srfi/33/bitwise.scm b/lib/srfi/33/bitwise.scm
index d0ac59f1..4ae8840f 100644
--- a/lib/srfi/33/bitwise.scm
+++ b/lib/srfi/33/bitwise.scm
@@ -38,7 +38,7 @@
       -1
       (integer-length (- i (bit-and i (- i 1))))))
 
-(define (mask len) (bitwise-not (arithmetic-shift -1 len)))
+(define (mask len) (- (arithmetic-shift 1 len) 1))
 
 (define (bitwise-merge mask n m)
   (bit-ior (bit-and mask n) (bit-and (bitwise-not mask) m)))