[quote author=Nick Gammon link=topic=94386.msg845720#msg845720 date=1341182059]
Still, is it teaching Unix or microcontrollers?[/quote]
It could be either, or both. Or neither: as I mentioned in my earlier reply there is a large segment of embedded Linux applications that fall in between "PC-like" and "Arduino-like". And there will be many, many more in future: as CPU power gets cheaper, things that are currently "luxuries" (like talking+listening cars and fridges that monitor their contents and download shopping lists to smartphones) will move further down into the middle class mass market.
If Unix, you can probably get some cheap second-hand PCs which people throw out when they upgrade to Windows 8 or whatever.
"Probably" may be marginally-sufficient if you're trying to put together a lab for the 4 or 5 geeks in your neighborhood Boy Scout troop. It doesn't come anywhere close if you're trying to plan a curriculum even for a single school, much less a district or a whole state. It's one of many approaches (like scrounging motors from old printers) that are great for one hacker, or a few, but don't scale up. Especially when you're trying to get them implemented by teachers who are only semi-geeky (if that).
If what I have seen locally is anything to go by, the Education Department will mandate that every school uses Windows, so the question might be a bit academic.
Prosecute a few of them for treason. That'll wise 'em up ]