Fennel works anywhere that Lua works. It tries to be a fairly transparent layer over Lua. For example it's become popular in the Neovim community. You can even set up Lua to interpret Fennel code at import time, no need for a separate "compilation" step to generate Lua code.
Whereas I wouldn't expect a CL implementation that compiles to Lua to work so seamlessly.
Whereas I wouldn't expect a CL implementation that compiles to Lua to work so seamlessly.