There’s a fantastic showcase of succesfull Common Lisp software on lisp-lang.org: http://lisp-lang.org/success/ so go there first.However all are not open source and it doesn’t list new or not so awesome but very cool or interesting software. That’s what we’ll do here to see that yeah Lisp is used today and to have code bases to look at.If you are looking for CL libraries, you of course had a look to the Awesome CL list.