Simillimum is a fork of SourceMod.
Right now it serves as a playground for those who would like to contribute to a more open repository.
It's not meant to be as a competitor, Simillimum may not be in a usable state (although we aim to only accept tested changes to the core) and it uses experimental code.
Anyone interested in becoming a contributor should get in touch with Zephyrus.
Simillimum will always maintain ABI compatibility with SourceMod.

2013.05.23

• Forked SourceMod
• Changed all SourceMod references to Simillimum while keeping ABI compatibility
• New signature scanning algorithm using a version of the Boyer-Moore-Horspool algorithm
• Introduced a new gamedata type for POSIX platforms to prevent offset breaks in case of updates
• Converted the sdktools/game.cstrike.txt gamedata to use Dynamic Offsets
• Added option to core.cfg to enable/disable listing of extensions and plugins
• Updated SQLite libraries to the latest version so we can benefit from its smaller memory footprint
  and better performance thanks to memory mapped I/O

2013.05.24

• Updated cURL libraries
• Minor cleanup
• Swapped the MySQL connector to the connector of MariaDB
• Added native HandleError:GetHandleStatus(Handle:hndl)
• Updated SDKHooks gamedata for CStrike to utilise Dynamic Offsets
• Add support for CSS to the ExtinguishEntity function

2013.05.25

• Updated makefiles and msvc solutions
• Refactored and merged a few patches by Afronanny:
• Using @aim while specatating someone will select the spectated player now
• Added AwardClientAchievement native
• Fixed a crash with Precache natives if they are supplied a bogus string

2013.05.26

• Added initial LUA support, considered highly experimental, stuff:
  • http://i.imgur.com/5Mi7Kdi.png
  • http://pastebin.com/aMcTVLQQ
• More cleansing

2013.05.27

• A lot of LUA improvements
• Finished updating makefiles so we can remove ambuild completely

• Major cleanup
• Expose cURL functions to plugins
• Implement a Socket extension without Boost dependencies
• Use the Boyer-Moore-Horspool algorithm for strstr/stristr
• Review all string handling functions and use a faster algorithm where possible
• Convert more gamedata to use dynamic offsets
• Expose Trie iteration to plugins
  • Write a trie iterator that doesn't actually suck......
• Major improvements to the default plugins
• Add a universal way to change the players' name
• Implement color code formatting to PrintToChat and PrintToChatAll
• Add full LUA support:
  • Add plugin hash support for plugin blacklist
  • Begin exposing natives to LUA
  • Rewrite all stock plugins in LUA
  • Add an exception handler to log all errors
  • Modify ExecuteString to use formatting