[eel]

It's a shame that Lua did not evolve in a more backwards-compatible manner. In addition to Roblox, lots of others projects started adopting Lua 5.1 as a scripting language in the late 00s. Lua itself is now at 5.4, but it did not keep backwards compatibility. LuaJIT and related projects pretty much only support 5.1. It's similar to the situation Python had with 2.x/3.x, except that the majority of Lua users I am aware of are preferring to stay with the older 5.1.

[thrance]

I think it's even worse than that, luau and luaJIT have evolved in different directions than the official lua project, such that they are now all sublty incompatible with each others. They all branch from lua 5.1 but it feels like there isn't an offical standard anymore.

[parenwielder]

At the very least, there's a common core of Lua 5.1 that works across Luau, LuaJIT, and PUC Lua, so it's not as if there's no standardization here. We definitely aspire to include _more_ than just Lua 5.1 in Luau though.

[kragen]

The huge difference is that the Lua community doesn't attack people publicly for maintaining backward compatibility, so it's generally pretty easy to write code that works across a wide range of Lua versions.

[giraffe_lady]

It's hard to get reliable numbers on this but I believe 5.1 and 5.2 are both more popular than 5.4 which has been out for five years now. And I don't think 5.3 ever surpassed either of them. I'm not sure about luajit it gets a lot of attention but I don't see it around all that much.

[johnisgood]

LuaJIT includes features from newer Lua versions (5.2 and 5.3), and more.

See https://luajit.org/extensions.html.