Share 'Loop Machines and Loop Software'

I was watching this video: Jammin' on the Diddley Looks like a lot of fun. I've been thinking about loop machines for quite some time, but I don't really have the $$ to buy one. However, I do have a stack of computers and a couple laptops that could probably run software that will do the same. Does anyone know of such software, or a good loop machine for the low budget folks. Thanks!