The thing is I don't want them to be passive media consumers; they've had next to zero screen time so far (eldest is three, youngest has just turned one) and I'd like to keep it that way w.r.t. entertainment media (i.e. not the awful "four year old parked infront of YouTube for an entire day" model).

So I'd like to build them a rig that encourages experimentation and deep learning, and which can be extended later to include interesting projects like robotics. Ideally something close to a modern version of my own childhood experience, which was a microcomputer ( http://en.wikipedia.org/wiki/Amstrad_CPC#CPC464 ) that when powered on quickly dropped into a (BASIC) REPL that gave instant feedback.

I was thinking of building a setup with the following:

- A decent mechanical keyboard. I currently use a Unicomp with an integrated trackball, and my three year old already enjoys 'typing' on that, and it's handily indestructible. http://www.pckeyboard.com/page/UKBD/UB404LA

- A Raspberry Pi 2. I've used an original Raspberry Pi for a few projects now (most recently controlling a DSLR for time-lapse photography) and I love the thing. It's close to the old micros in spirit: plug in, power on, and it's running. http://www.raspberrypi.org/raspberry-pi-2-on-sale/

- An LCD monitor. I was thinking a matte-finish 24" or larger, high-res with HDMI. Nothing out of the ordinary there.

The real question surrounds software. After attending RubyConf and seeing a Sonic Pi ( http://sonic-pi.net/ ) demo I'm definitely keen on that, but otherwise I'd really appreciate some guidance. What software would people recommend to get children interested in computing, and also impart good skills?

Back in the olden days I'd have gone straight to LOGO and a turtle robot.