The Tclkill package provides a cross-platform "kill" command. See http://www.fpx.de/fp/Software/tclkill/ The motivation is to terminate background processes that were started with [exec], which in this case returns a (list of) process identifier(s). The discussion on the [kill] provides various references to packages that provide this functionality, e.g., [TclX] on Unix, [TWAPI] on Windows, and various external utilities, but neither is cross-platform. This package includes a DLL for Windows, a shared library for Linux/x86, and on other platforms it does "exec kill $pid". <> Package