I started a programme at my son's primary school to teach rudimentary programming skills using Computercraft, but ultimately found the Minecraft environment proved too distracting for the children. Supervised, they did absolutely fine, and Computercraft essentially provides a Logo like environment using a modern programming language which is superb. Computercraft is engaging, and setting up tasks for the kids to perform with the turtles was instructive and fun. Left to their own devices however, the children were more inclined to just mess around in the sandbox. I still think Computercraft can be a useful tool for an educator, but it absolutely requires supervision and guided learning.