Writing a Just-In-Time (JIT) compiler is a complex task. For that reason, libraries like libgccjit were developed to ease the process; but most often than not, JIT compilers are written from scratch, and only target one or two architectures.

In this talk I am going to present GNU Lightning, a cross-platform library that can be used to generate machine code at run-time. I will present its strengths and weaknesses, how to use it, and why I decided to use it in my JIT compiler project.