killing thread after timeout

[Jacek Popławski]

Hello.

I am going to write python script which will read python command from 
socket, run it and return some values back to socket.

My problem is, that I need some timeout. I need to say for example:

os.system("someapplication.exe")

and kill it, if it waits longer than let's say 100 seconds

I want to call command on separate thread, then after given timeout - 
kill thread, but I realized (after reading Usenet archive) that there is 
no way to kill a thread in Python.

How can I implement my script then?

PS. it should be portable - Linux, Windows, QNX, etc