There's a new major version of the Guile language implementation coming, and it's on average around twice as fast as Guile 2.2. Guile 3, expected to be released in Spring 2019, achieves these improvements by adding on a just-in-time compilation system to its virtual machine. Co-maintainer Andy Wingo will walk you through how we managed to achieve these improvements while not increasing startup latency, and give tips and tricks for early adopters.