It is “SBCL or proprietary” nowadays. LW and ACL are fine but are pricy and well, proprietary.
CCL is all but dead.
ECL has a kind of limited niche, and is not as advanced as SBCL(e.g.: MOP). Same goes for ABCL. Also, ABCL is kind of slow.
Clasp is somewhat interesting, but it also has a limited niche (C++ interop) and is also not as advanced as SBCL.
GNU implementations are dead(GCL, CLISP)
Everything else is as dead as GNU implementations.
Well, I was judging by its official page and Sourceforge activity, which seems negligible. However, Gitlab also does not seem very active (6 commits this year, despite lots of open bugs). The development is almost stalled. It is on life support, at best.