Comment by ksymph
19 hours ago
Lua's nature as a primarily embedded language means backwards compatibility is not guaranteed between any version. If 5.2 was a language fork then so was 5.3, 5.4, 5.5, etc. (5.2 did have some more significant changes though)
For that reason luajit staying at ~5.1 actually works in its favor. Rather than trying to follow the moving target of the newest version, it gives a robust focal point for the lua ecosystem, while modern versions can be developed and continue to serve their purpose in embedded systems and whatnot where appropriate.
I don't see a reason not to update LuaJIT still. Changes in Lua aren't just version numbers, it should be improving something, meaning that would be missing in LuaJIT.
LuaJIT does have some backported features from newer versions. But Mike Pall -- the mad genius behind LuaJIT -- has made it clear he doesn't agree with many of the changes made in newer versions, hence why it's staying where it's at.
the beauty of open source is there's nothing stopping you! this might be your calling. best of luck