Neovim will support PUC Lua 5.1 for both user scripts as well as internal lua logic. The external lua-client[1] supports luajit and PUC lua and the CI[2] runs PUC lua on every PR and commit.
The Neovim patch[3] to add built-in lua scripting will support both luajit and PUC lua.
The Neovim patch[3] to add built-in lua scripting will support both luajit and PUC lua.
I also updated the FAQ[4] to avoid confusion.
1: https://github.com/neovim/lua-client
2: https://travis-ci.org/neovim/neovim/jobs/162545247
3: https://github.com/neovim/neovim/pull/4411
4: https://github.com/neovim/neovim/wiki/FAQ