The authors for the main code in alphabetical order:

Bunkus, Moritz (Mosu) <moritz@bunkus.org>
    * Almost everything

Cannon, John (spyder482) <spyder@matroska.org>
    * MPEG ES parser code

Coalson, Josh <j_coalson@yahoo.com>
    * support for libFLAC 1.1.3

Galassi, Damiano <damiog@gmail.com>
    * Bugfix for timecodes in MP4 files with edit lists and B frames

Hakobyan, Sergey <sergey.hakobyan@viragelogic.com>
    * Support for creating missing output directories
    * Using the attachment names in Matroska files for extraction

Taniura, Hiroki <zuntakapokoten@gmail.com>
    * Japanese translation

Jacobs, Aurelien <aurel@gnuage.org>
    * Support for RealAudio v3 in RealMedia files
    * Bugfixes (e.g. BZIP2 compression)
    * Support for float PCM tracks

Le Guen, Nicolas (Goldenear) <nleguen@pepper-prod.com>
    * Enhancements and updates to the "CUE sheet to tags & chapter
      conversion" process
    * Small updates to mmg and the MIME type list

Lee, Dean <xslidian@gmail.com>
    * Chinese Simplified translation
    * Chinese Traditional translation

Lhomme, Steve (robux4) <steve.lhomee@free.fr>
    * Fixes for compilation with MSVC
    * Enhancements and fixes to the XML chapter parser
    * The complete VobButton handling
    * The complete WAVPACK handling
    * Support for SimpleBlock usage
    * The CorePicture XML reader

Matsnev, Mike (Haali) <mike@po.cs.msu.su>
    * CreateFileUtf8() function
    * Windows implementation for vsscanf
    * The MPEG header generation for VobSub extraction

Mierzejewski, Dominik (Rathann) <dominik@greysector.net>
    * Patch for proper Boost detection for cross compilation builds

Millan, Robert <rmh@aybabtu.com>
    * MIME type recognition via libmagic
    * Fix for a malloc bomb in the PCM handling

Mistry, Shailesh L <shailesh.mistry@milan.eclipse.co.uk>
    * Fixes for compilation of avilib with cygwin

Niemayer, Peter <niemayer@isg.de>
    * The DTS code (reader, packetizers, dts_common)
    * The use of posix_fadvise in the mm_io_c class

Pettenò, Diego <flameeyes@gentoo.org>
    * Support for liblzo2

Pettersen, Vegard <vegard_p@broadpark.no>
    * Extended support for converting CUE sheets to tags & chapters

Rice, Matt <topquark@sluggy.net>
    * Extraction of h.264 into proper h.264 ES streams

Schmuland, Todd <tschmula@gmail.com>
    * Bugfix for VobSub extraction
    * Bugfix for VobSub muxing
    * Enhancements for MPEG program stream parsing (invalid padding
      packet lengths)
    * Hack for adding 'stop display' commands to VobSub packets without
      a duration

Stone, Jory (jcsston) <jcsston@toughguy.net>
    * Fixes to mkvinfo's GUI

Wu, Dong-Jun <ziyawu@gmail.com>
    * Chinese Traditional translation

Zenkov, Mihail <mihail.zenkov@gmail.com>
    * Support for reading MP2 audio tracks from OGM files

?, ? (Lefungus)
    * Avoid several compiler warnings

?, ? <ogg.k.ogg.k@googlemail.com>
    * Support for Ogg Kate in mkvmerge and mkvextract

-------------------------------------------------------

Stuff that was developped externally and only included/patched in mkvtoolnix:

avilib:
    * Johanni, Rainer <Rainer@Johanni.de> (original source code)
    * Östreich, Thomas <ostreich@theorie.physik.uni-goettingen.de>
      (lots of modifications in transcode)
    * Bunkus, Moritz <moritz@bunkus.org> (lots of modifications in
      ogmtools and mkvtoolnix)
    * probably others