This is a project that has been in development for years now and also makes use of the Cleavir compiler framework (
https://github.com/s-expressionists/Cleavir), which is being developed as part of another new Common Lisp implementation called SICL (
https://github.com/robert-strandh/SICL).
Congrats to the CLASP devs, this is a huge accomplishment and it's really exciting to see a new CL implementation get a 1.0 release.