system("prog.exe") is great if you don't care about the input/output of the program. You might also want to look into the 'popen()' function -- popen() lets you get a file descriptor so you can read or write to the programs standard input/output. For example, you could popen('ftp.exe') and write ftp commands to it using fputs or whatever, or popen('top') and read process information from the 'top' command just like it was a file.

Regards,
Meredith Shaebanyan