Please see the attached ugdb.c. It supports multiple inferiors/threads, stop/cont, clone/exit. It doesn't report W/X when the process exits yet, but this is only because I'd like to discuss the current problems with the exited leader first, then implement this as a separate change. Any code review is very much appreciated. Problems: - It doesn't support all-stop mode. Please tell me if this is needed. I hope not, this needs a lot of nasty complications :/ - We should discuss utrace limitations: UTRACE_RESUME races/problems, utrace_prepare_examine() issues. - I just finished this code, and it doesn't work with gdb ;) I will investigate tomorrow, but I am almost sure gdb is wrong. Oleg.