The following patch adds SYS:GETPID which works by making the abcl wrapper shell script store the current PID as a system property. For some reason, I see the following behaviour: tcr@thaleron:~/src/from-upstream/abcl$ abcl-svn Armed Bear Common Lisp 0.19.0-dev Java 1.6.0_17 Sun Microsystems Inc. Java HotSpot(TM) Client VM Low-level initialization completed in 0.47 seconds. Startup completed in 1.099 seconds. Type ":help" for a list of available commands. CL-USER(1): (sys:getpid) Unable to autoload SYSTEM:GETPID tcr@thaleron:~/src/from-upstream/abcl$ I.e. the patch is not yet finished; I hope that it'll be clear what's missing to the more experienced ABCL hackers on the list. On Windows, (SYS:GETPID) will just return NIL. There may be some way to do similiar magic with batch files, but googling didn't reveal anything promising. -T.