I turned my daughter on to this at age 4 and within an hour she had figured out loops, variable and collision detection. I'm particularly impressed with the way they modeled loops, which is always a hard thing to explain to new developers.
The only problem we had to do with the amount of screen real estate needed, she had a 12" iBook with a 1024x768 display and it was almost unusably cramped. On modern machines, I'm sure it would be no problem.
The great thing about Squeak is it lets you do some cool stuff first and learn the hard stuff later, once you've built up some momentum without throwing away the principles common to almost all software development platforms.
I'm particularly impressed with the way they modeled loops, which is always a hard thing to explain to new developers.
I remember trying to learn Perl from one of the O'Reily books when I was 11 or 12. I was following the examples and generally enjoying myself until I came to one with a while loop. I was ticked off that it was looping automatically and I couldn't see why. I was expecting that I needed to say when to go back to the beginning of the block. ...maybe c would have been better then.
I'm part of the Scratch Team and it's great to see our project here on HN! I've been leading the development of the web site and I'd be curious if there are any HN volunteers who might be interested in contributing their expertise in this effort. We're particularly interested in people with experience in scaling up web applications or Linux experts that could help us iron out some of the issues we have with Scratch on that platform (Ubuntu specifically).
If I had to pick just one thing that Scratch gets right that other programming languages should strive for, it would be the immediacy with which a beginning programmer can get compelling results through trying things. I've seen many would-be programmers lose interest because the process to get a desired result is too abstract and prolonged; the inertia is too great. The ability to get results quickly reinforces further exploration of the system. Novices can build up to an understanding of data structures, algorithms, and how to structure code.
There are some grown-ups who play with scratch too; on the project page they have a numerical procedure for speeding up the built in functions like square root and sin to implement collisions off round objects.
The only problem we had to do with the amount of screen real estate needed, she had a 12" iBook with a 1024x768 display and it was almost unusably cramped. On modern machines, I'm sure it would be no problem.
The great thing about Squeak is it lets you do some cool stuff first and learn the hard stuff later, once you've built up some momentum without throwing away the principles common to almost all software development platforms.