I have no idea why he did it instead of forking SBCL, but I thank him for it dearly. Lisp on LLVM is one of the things that will save it from dying. LLVM comes with extreme portability (future proofing to future platforms) and lots of industrial strength tooling. SBCL is very good, but it’s hard to say how long it will keep being developed.
It's easy to say something like this in retrospect But even after working on this for a couple of years I have no idea how I would get started with SBCL. There was a team at Google that tried to add a llvm backend to SBCL and they stopped working on it after a year. I don't want to knock SBCL - it's an amazing compiler! But I think there are way too many problems that I would have had to solve, all at once, to get C++ and SBCL to interoperate.
> I have no idea why he did it instead of forking SBCL
It's basically explained in the video. He forked ECL, because he wanted to have a CL implementation based on LLVM and very deep C++ integration. ECL is already a C-based Common Lisp.
> SBCL is very good, but it’s hard to say how long it will keep being developed.
