Execute A program from a Program!

Aside from using an I/O string command to execute another program from inside a currently running program, is there any other ways to do this?

Thanks

If you want it to execute as anothe process, Runtime.getRuntime().exec("...the command to execute...");

If you want it to run in the same process space, you can simply call the 'main' method of some class directly.

exec will return a process and you can deal with the return messages