The Wolfram Language immediately allows you to call both standalone programs and individual functions or methods within running programs. The Wolfram Language's architecture allows external functionality to be represented in a symbolic form that can immediately be manipulated within the Wolfram Language—and that often makes access to external functionality from within the Wolfram Language more convenient even than from its own native environment.
Basic External Program Operations
Run— run an external command-line program (!prog to run as a shell escape)
RunThrough— feed standard input to an external program and capture output
SystemOpen— open a file, URL or other target on your computer system