[dlctr]

The arduino yun [1] combines an linux-based SoC with a microcontroller on a single board. So you can have both, networking and applications in practically any language, and an internal interface to a microcontroller.

For only accessing a rs232 serial port over ethernet, there are easier solutions. But if you need multiple of such ports, sensor access, etc. its quite a nice combination.

[1] http://arduino.cc/en/Main/ArduinoBoardYun?from=Main.ArduinoY...