Hello, I've been having these 2 implemented in psutil for a long time. On POSIX these are convenience functions using os.kill() + SIGSTOP / SIGCONT (the same as CTRL+Z / "fg"). On Windows they use undocumented NtSuspendProcess and NtResumeProcess Windows APIs available since XP. The same approach is used by ProcessHacker and - I suppose - pssupend.exe, both from Sysinternals team. It must be noted that there are 3 different ways to do this on Windows (https://stackoverflow.com/a/11010508/376587) but NtSuspend/ResumeProcess appears to be the best choice. Possible use case: <<PsSuspend lets you suspend processes on the local or a remote system, which is desirable in cases where a process is consuming a resource (e.g. network, CPU or disk) that you want to allow different processes to use. Rather than kill the process that's consuming the resource, suspending permits you to let it continue operation at some later point in time.>> Thoughts? -- Giampaolo - http://grodola.blogspot.com