Due to the Maker Monday I didn't go to last night, there's been some chat on Slack about Lego MindStorms kits. We bought our kids the original RCX kit and I bought a 1999 O'Reilly book which I didn't find time to read and was too hard for children who liked Lego bricks more than robots (One used Lego in his final fine art piece and the other is an architect, so I don't begrudge the investment.) I probably decided I needed to learn C first because it mentions:
Not Quite C, NQC http://bricxcc.sourceforge.net/nqc/ and
Alternative Lego OS https://sourceforge.net/projects/legos/
"Download legOS Alternative Lego OS for free. legOS is an alternative software environment for the Lego Mindstorms Robotic Invention System. The intent is to allow developers to write C and/or C++ code for the RIS platform."
which has a link to: http://brickos.sourceforge.net/
and I found a Debian Linux for the latest MindStorm: LEGO NXT/EV3.
"ev3dev is a Debian Linux-based operating system that runs on several LEGO MINDSTORMS compatible platforms including the LEGO MINDSTORMS EV3 and Raspberry Pi-powered BrickPi."
The BrickPi upgrades MindStorm to a Pi.