I took advantage of the weekend to upgrade my machines to Clozure CL 1.8. As usual, installation was a snap. Just get the distribution with SVN:
svn co http://svn.clozure.com/publicsvn/openmcl/release/1.8/darwinx86/ccl
for Mac OS X and then
ccl64 -n ? (ccl:rebuild-ccl :full t)
and you're done. Users of other platforms will need to change
darwinx86 to the directory appropriate for their systems as explained on the Getting Clozure CL page.
Lisp programs compiled with CCL 1.8 run a bit faster than those compiled with CCL 1.7 and, of course, there are various bug fixes and other clean up as described in the release notes.
I've only started using it but so far I'm happy with what I see. There are no obvious incompatibilities except for a couple of improvements to the
directory function, and a minor change to the way the kernel handles a single command line argument that makes it easier to call standalone binaries. With performance enhancements and bug fixes, there's not much to dislike.