Image via WikipediaAt the request of Bonny Glen, here's a list I've compiled of links to help kids learn computer programming. She's looking for Mac-compatible, we're PC, but hopefully some are useful. Just FYI, my older son started with an enrichment class using a really old version of Logo, has taken a few robotics summer workshops, and is currently trying to teach himself computer gaming coding.
Teaching your kids how to write computer programs is an essay by Marshall Brain, creator of HowStuffWorks.com. It includes a lot of links.
Scratch -- Free Kids Programming Language from MIT
Guido van Robot: Guido van Robot, or GvR for short, is a programming language and free software application designed to introduce beginners to the fundamentals of programming. GvR runs on Windows, Macintosh, and GNU/Linux, in a variety of languages! It's great in both the classroom and the home as a way of introducing people to the basic concepts of programming.
Alice: Free teaching tool designed to be a student's first exposure to object-oriented programming. It allows students to learn fundamental programming concepts in the context of creating animated movies and simple video games in 3-D.
How to Think Like a Computer Scientist: Learning with Python 2nd Edition: Open book project
by Jeffrey Elkner, Allen B. Downey, and Chris Meyers