Say I download a tarball that has a number of projects in it: $ tar xzvf fooprojects.tgz fooprojects/neato/neato.asd fooprojects/neato/neato.lisp fooprojects/stuff/stuff.asd fooprojects/stuff/stuff.lisp fooprojects/xyz/xyz.asd fooprojects/xyz/xyz.lisp If these are now unpacked in ~/src/fooprojects/, how can I add that tree to my ASDF source registry by calling ASDF functions? Say a few minutes later I download another tarball with a number of projects in it: $ tar xzvf barprojects.tgz barprojects/awesome/awesome.asd barprojects/awesome/awesome.lisp barprojects/stump/stump.asd barprojects/stump/stump.lisp barprojects/tapper/tapper.asd barprojects/tapper/tapper.lisp If these are now unpacked in ~/src/barprojects/, how can I add that tree to my ASDF soruce registry by calling ASDF functions, without losing the previous fooprojects registration? Thanks, Zach