[anigbrowl]

Good point. On the other hand, if you've got some breathing room to see how practical it is, it's conceptually pretty simple. Start by finding out why they want to go Linux rather than using something like Quickbooks (which is not that expensive overall). Then start hacking something together with MySQL to see if you like it. I'd lean towards using python because it's friendly, but C remains popular on Linux.

There's a book called Beginning Linux Programming by Stones and Matthew which is a great introduction to the operating environment and key concepts, and nice to read. The use an example database application of a CD collection/music store, developed/extended in a variety of programming contexts and languages. I'd say obtain the book and curl up with it for 3 days, it's worth owning a copy anyway and you'll know after a few days whether tis feasible for you or you're entering a world of hurt.