Been travelling and working too much on other stuff lately to make much progress with Systrace. The ptrace version works reliably enough on Linux without the kernel patch. Although, it sometimes still leaves zombie processes behind which is kind of annoying. Performance without kernel patch takes a 100% hit, too. Marius has promised to revamp the kernel patches and make them more Linux friendly. Maybe, we will be able to get them into mainline Linux then. Stay tuned.