Dear lispers,
with the recent release of LispWorks 7 (congratulations to the LispWorks team!), each and every maintained CL implementation now provides ASDF 3, and ASDF 2 can be declared officially dead. Adieu, ASDF 2, you served your purpose, but you won't be missed.
I propose that free software libraries (including ASDF itself) may safely assume ASDF 3 everywhere and drop support for ASDF 2 or earlier.
Note: I didn't count GCL as an actively maintained CL implementation, which is only slightly harsh. Maintained (and ship with asdf 3): abcl ccl clasp clisp cmucl ecl mkcl sbcl allegro lispworks Unmaintained (but have worked at some point with asdf): gcl mcl xcl cormanlisp genera mocl scl
—♯ƒ • François-René ÐVB Rideau •Reflection&Cybernethics• http://fare.tunes.org "Computer programming is omnipotence without omniscience." — Prospero, as cited by Eliezer Yudkowsky