I've integrated some DTrace [1] probes into R. Namely a probe which fires on fuction entry and return and one which fires before / after a garbage collection. Is there any interest in merging something like this into R-devel? If yes, I'd like to discuss which probes and what data would be useful / interesting from a developers standpoint. Greetings from Dortmund, Olaf Mersmann [1] http://www.sun.com/bigadmin/content/dtrace/