I hi have just ordered a couple of beaglboards for experimenting. I know that it can rub Ubuntu and many other flavors of linux. 
Does that mean it can run all the trivial software that run on Ubuntu? 
Will the python and ruby interpreters work just the way they work on PC ?
The interpreters do not need to be compiled from source, as the Ubuntu arm distribution has python in its repository as a deb.  I was able to write my python scripts on my Ubuntu box and transfer them to the beagleboard without any changes.  Performance so far has been surprisingly good, as I'm using the python script as a bridge between the real-time sound processing/synthesis language supercollider and a motor control board that communicates over USB-serial.
Can beagleboard run python or Ruby programs?