They're really pretty different so if depends on your goals and your environment. If you're scripting something Lua-scriptable like OpenResty/Haproxy, or you want to piggyback off the Lua ecosystem of modules you're looking at Fennel as your choice. If you want more built-in batteries and you aren't tied to Lua, you may prefer Janet although the ecosystem is young. If you like Clojure but don't want to use regular Clojure, I guess you'd prefer Babashka. Of the 3 I've not used Babashka, so I'm not sure the sell here. Is it just an alternative runtime I guess?