With the said RaspberryJuice you don't need to have a Raspberry Pi.

I wrote a RaspberryJuice+Python command server so you can have run python functions inside minecraft. [0]

[0] https://github.com/wensheng/JuicyRaspberryPie

Because the Pi version of minecraft has an api http://wiki.vg/Minecraft_Pi_Protocol Also if you have younger kids check out https://github.com/scratch2mcpi/scratch2mcpi run a scratch extension on your pc and place blocks in minecraft on the Pi. It goes down well at our local coderdojo.

The scratch2mcpi sounds great. I mentor at a local coderdojo as well.