LuaJIT 2.0 is the current stable branch. This branch is in feature-freeze — new features will only be added to LuaJIT 2.1.

Current Status

LuaJIT ought to run all Lua 5.1-compatible source code just fine. It's considered a serious bug if the VM crashes or produces unexpected results — please report this.

Known incompatibilities and issues in LuaJIT 2.0: