This is a brief overview of user-visible changes in AdPlug.

Changes for version 2.1:
------------------------
- New format support:
  - ADL: Westwood ADL File Format
- Added OPL3 support:
  - A2M: AdLib Tracker 2 versions 5-8
- All players are endian-clean now.
- Lots of security fixes (thanks to Luigi Auriemma).
- Fixed volume handling in AMD player.
- Fixed a buffer overflow in ROL player (thanks to HIGUCHI Daisuke).
- Fixed vibrato & volume slides in D00 player (thanks to Dennis
  Lindroos).
- Removed superfluous exit() call in RIX player (thanks to Martin
  Michlmayr).
- Enhanced generic Protracker player features:
  - Supports up to 32 channels
  - OPL3 output support
  - New behavior flags and commands

Changes for version 2.0:
------------------------
- New format support:
  - MSC: AdLib MSCplay
  - RIX: Softstar RIX OPL Music Format
- Added OPL3 support:
  - RAW: RdosPlay RAW
- Dual OPL2 and OPL3 support (OPL3 only in non-free version).
- This version is not binary-compatible with older versions!
  All linked applications need to be recompiled.
- License change: Ken Silverman permitted to relicense his
  emulator under the LGPL. It is included in the free distribution
  now.
- Changes to IMF player:
  - Supporting Adam Nielsen's tag format now.
  - Files ending in .IMF now have a default timer refresh rate of
    560Hz. All other files have a rate of 700Hz. Please rename your
    files accordingly or use the AdPlug database.
- CMF player supports rhythm mode now.
- S3M player handles repeating commands correctly now.
- MS Visual C++ and OpenWatcom build systems not actively supported
  anymore. They are still available in the contrib directory though.

Changes for version 1.5:
------------------------
- New format support:
  - XSM: eXtra Simple Music
  - DRO: DOSBox Raw OPL
  - LDS: LOUDNESS Sound System
- Added support for .adlib files to IMF player.
- Reverted fmopl OPL2 emulator to old LGPL'd version, so
  AdPlug is now completely free (LGPL) again. Please read the
  README file for details.
- Added Ken Silverman's YM3812 emulator again. The portability
  issues have been fixed.
- Added a test-suite.

Changes for version 1.4:
------------------------
- Documentation changed into Texinfo format.
- New, modularized file loading framework.
- Now using 'libbinio' for platform-independant binary I/O.
- Added database framework for storing music file information.
- Uses newest fmopl OPL2 emulator version 0.60 from MAME 0.66.

Changes for version 1.3:
------------------------
- Completely new build system for DOS and Windows.
- Centralized debug management.
- Added a whole bunch of new developer documentation.
- Developer documentation is now using troff formatting language.
- Much more flexible Protracker player.
- New or corrected IMF timer rates for the following games:
  - Duke Nukem 2
- New format support:
  - SNG: Adlib Tracker 1.0
  - CFF: BoomTracker 4.0
  - DTM: Defy Adlib Tracker
  - DMO: Twin TrackPlayer

Changes for version 1.2:
------------------------
- Added a whole bunch of new players:
  - SAT, ROL, SNG, XAD, XMS, MAD
- SA2 player now handles version 7 files.
- GCC 3.x compatibility.
- Compiles on FreeBSD (and maybe many more flavors).
- Now using GNU autotools for UNIX builds.
- New OPL disk writer that creates RdosPlay RAW files.
- Reordered source directory structure (removed players directory).

Changes for version 1.1:
------------------------
- Added MKJ, DFM and BAM players.
- Removed Ken Silverman's YM3812 emulator due to portability issues.
- Fixed memory leak in SNG player.
- Made AdPlug a real library.
- Added lots of documentation.