I've believe I've written code that can load a compiled asdf system from a jar file. Final testing is pending the patch for loading a compiled file from a subdirectory of a jar. In order to do that I needed to do 3 things. 1) Patch probe file so that it understands jar:file pathnames 2) Patch truename so that it understands jar:file pathnames 3) Create a new asdf op that knows to load only the compiled files. These patches are in http://svn.mumble.net:8080/svn/lsw/trunk/patches/jarfile.lisp I used advise (http://svn.mumble.net:8080/svn/lsw/trunk/util/encapsulate.lisp) to patch, probe-file, directory, and truename, but don't mind merging the changes into source if it's deemed that they are the right thing. I'd submit the code for advise too (adapted from MCL), but it's not quite cleaned up yet. The asdf op is in that file too. It's a bit hacky because I use asdf-binary-locations[1] and I didn't see how to cleanly integrate it. If someone knows how to drive asdf better than I do, please suggest a better way. There's still a nit in that if you load the system a second time it warns about file-write-date not working. I'm not sure file write date should return for a jar:file pathname. The write date of the containing jar? FWIW, I think that you should consider having asdf-binary-locations be part of the standard distribution. As ABCL is under active development I was always running into issues with stale fasls, but no more since I've been using it. -Alan [1] http://common-lisp.net/project/asdf-binary-locations/ laptop:~/ % jar tf test.jar META-INF/ META-INF/MANIFEST.MF bar/ bar/armedbear-0.18.0-dev-darwin-unknown/ bar/armedbear-0.18.0-dev-darwin-unknown/bar1.abcl bar/armedbear-0.18.0-dev-darwin-unknown/bar2.abcl bar/bar.asd CL-USER> (advise load (if (eql 0 (search "jar:file" (namestring (car arglist)))) (format t ";; would have loaded ~a~%" (car arglist)) (:do-it)) :when :around :name stub) #<FUNCTION (ENCAPSULATE::ADVISED 'LOAD) {ACB16B}> CL-USER> (load "jar:file:/Users/alanr/repos/lsw/trunk/patches/test.jar!/bar/bar.asd") ; Loading jar:file:/Users/alanr/repos/lsw/trunk/patches/test.jar!/bar/bar.asd ... ; Loaded jar:file:/Users/alanr/repos/lsw/trunk/patches/test.jar!/bar/bar.asd (0.0030 seconds) T CL-USER> (asdf::oos 'asdf::load-just-fasls-op 'bar) ;; would have loaded jar:file:/Users/alanr/repos/lsw/trunk/patches/test.jar!/bar/armedbear-0.18.0-dev-darwin-unknown/bar1.abcl ;; would have loaded jar:file:/Users/alanr/repos/lsw/trunk/patches/test.jar!/bar/armedbear-0.18.0-dev-darwin-unknown/bar2.abcl CL-USER> (asdf::oos 'asdf::load-just-fasls-op 'bar) WARNING: Missing FILE-WRITE-DATE for #P"jar:file:/Users/alanr/repos/lsw/trunk/patches/test.jar!/bar/bar1.lisp": treating operation #<ASDF::LOAD-JUST-FASLS-OP NIL {8C2182}> on component #<ASDF:CL-SOURCE-FILE "bar1" {B93BB6}> as done. WARNING: Missing FILE-WRITE-DATE for #P"jar:file:/Users/alanr/repos/lsw/trunk/patches/test.jar!/bar/bar2.lisp": treating operation #<ASDF::LOAD-JUST-FASLS-OP NIL {8C2182}> on component #<ASDF:CL-SOURCE-FILE "bar2" {7242FD}> as done.