[mdbauman]

As a fan of Lua, one complaint not mentioned in the article but that I think is relevant if you're starting to learn the language is that minor releases often contain breaking changes. This is fine - the maintainers can number things however they want I guess - but can be a bit annoying if you're expecting to read the latest 5.4 reference manual and then write an embedded script for something using a different 5.x runtime.

This is mostly relevant because when people talk about Lua's speed, they're usually talking about LuaJIT [1] which (iirc) was based on 5.1 and backported many 5.2 features.

So, if you're someone who's decided to use Lua for a specific use case, you may want to see if your target specifies a specific Lua version (ex. Roblox, LÖVE, PICO-8, OpenResty are mentioned in this thread and all use either LuaJIT or a subset of 5.1), or if you expect to need the performance of LuaJIT in the future.

Edit: formatting

[1]: https://luajit.org/luajit.html

[soapdog]

Lua versions are thoroughly explained in their documentation page which includes a page on versioning:

https://www.lua.org/versions.html

The very first section in that page is explaining how the versioning works:

  The releases of Lua are numbered x.y.z, where x.y is the version and z is the release.
  
  Different releases of the same version correspond to bug fixes. Different releases of the same version have the same reference manual, the same virtual machine, and are binary compatible (ABI compatible).
  
  Different versions are really different. The API is likely to be a little different (but with compatibility switches), and there is no ABI compatibility: applications that embed Lua and C libraries for Lua must be recompiled. The virtual machine is also very likely to be different in a new version: Lua programs that have been precompiled for one version will not load in a different version.

LuaJIT is fast but that doesn't mean that PUC Lua is slow. A lot of people say that Lua is fast when comparing it with other languages which are perceived as slow such as Python or Ruby, they might be talking about PUC Lua. Others are saying Lua is fast and comparing it to JS, C, and other fast languages, there is a great chance they're talking about LuaJIT. Anyway, I just wanted to say that PUC Lua while slower than LuaJIT and slower than many other languages is still speedy enough for most use cases it was designed for.