nvim-slime is a pure Lua implementation of https://common-lisp.net/project/slime/ for Neovim. It was adapted from this Textadept version https://github.com/chadvoegele/textadept-slime, which was originally inspired by https://github.com/jpalardy/vim-slime.
I just threw this together as a proof-of-concept. Probably a lot of things don't work. PRs welcome.
Using vim-plug,
Plug 'chadvoegele/nvim-slime'
MIT