Terra lang is pretty cool but Pallene and Terra are significantly different. Terra is a language built for multi-stage programming - basically like lisp quotes where you're jumping between something like a compile time context and a runtime context. It's embedded in Lua, and uses Lua as the compile-time language IIRC. Pallene is strictly compile-time. It is a Lua-like language with type hints that can compile to Lua or to C code that is optimized for use in Lua's C API. So if you had some Lua module that was frequently calling to C for whatever reason, all those calls come with a performance tax. Pallene aims to lessen that particular penalty. They have a white paper where it compares several algorithms with stock PUC-Rio Lua, LuaJIT and pallene against each other and it's pretty interesting where each tends to shine over the others.