This blog post gives background on how programming languages are implemented and how JITs work. It’ll introduce the implementation details of the Julia language, though it won’t talk about specific implementation details or optimizations made by more traditional JITs. Check out How JIT Compilers are Implemented and Fast: Julia, Pypy, LuaJIT, Graal and More to read about how meta-tracing is implemented, how Graal supports C extensions, the relationship of JITs with LLVM and more!