Congratulations! ECL is very mature, and this release seems to further solidify that aspect of the project. We've been using it heavily at our startup with no problems, embedded with c++. I think it's a very well done implementation.
If you're thinking of trying ECL out but emacs/slime is too much to have to learn, rlwrap, is a readline wrapper that makes the REPL very friendly. To integrate with c++, the ECL manual [1] is a decent reference.<p>[1] <a href="https://common-lisp.net/project/ecl/manual/" rel="nofollow">https://common-lisp.net/project/ecl/manual/</a>
Has anyone used the embedding aspect of ECL significantly? I've used ECL as a standalone Lisp system, and also done fairly trivial embedding where there isn't much more interaction than there would be if you communicated with an external Lisp system via a pipe. But curious how usable the API on the C side is for interacting with an embedded ECL, to call functions and pass data across the boundary in either direction (cl_object, cl_def_c_function, etc.). The documentation for that part seems pretty sparse.
An issue of ECL Quarterly was also published recently including some release coverage: <a href="https://common-lisp.net/project/ecl/quarterly/volume2.html" rel="nofollow">https://common-lisp.net/project/ecl/quarterly/volume2.html</a>.