OTServ 0.6.4
Client version: 8.60
Git version number 5195

Changes can be found here https://github.com/opentibia/server/commits/legacy.
This is the server which every other is based on ie.(TFS,Evolutions,Naxed) basicly all of them ! and is also maintained by the OTServ leaders ie.SimOne ,Remere

List of lua functions :
You can see the functions and their parameters in these files :
functions.lua and luascript.cpp and npc functions in /npc/scripts/lib/

Source code:
unpack 7zip and go into src
How to write bug reports : http:https://otland.net/threads/how-to-make-crash-report-otserv-and-tfs.59083/

OTServ Bug reports :
https://github.com/opentibia/server/issues?state=open

If you want to compile the server by yourself on windows/linux please take a look at this tutorial:
http:https://otland.net/threads/compiling-simple-otserv-msvc-2010-linux-compiling-the-source.218342/

From what I can say the server is most stablest distro over all and have all 8.6 features working as they should .