Open Source

The idea behind Open Source software is rather simple: when programmers can read, distribute and change code, the code will mature. People can adapt it, fix it, debug it, and they can do it at a speed that dwarfs the performance of software developers at conventional companies. This software will be more flexible and of a better quality than software that has been developed using the conventional channels, because more people have tested it in different conditions than the closed software developer ever could.

The Open Source initiative has started to make this clear to the commercial world, and very slowly, commercial vendors are starting to see the point. While lots of academic and technical people have already been convinced for 20 years now that this is the way to go, commercial vendors needed applications like the Internet to make them realize they could profit from Open Source. Linux has now grown past the stage where it was almost exclusively an academic system, useful only to a handful of people with a technical background. Now Linux provides more than the operating system: there is an entire infrastructure supporting the chain of effort of creating an operating system, of making and testing programs for it, of bringing everything to the users, of supplying maintenance, updates and support and customizations, etcetera. Today, Linux is ready to accept the challenge of a fast-changing world.
(http://www.faqs.org/docs/linux_intro)

Open Source software is actively developed for Linux and all major desktop environments such as Windows and Mac OSX. In addition, Samba, Apache, Open Office, Mozilla and Gimp are all very popular programs with K-12 teachers and students. TuxPaint, and other newbreedwoftare are also very popular multi-platform Open Source applications.

This article will provide you with a different perspective: http://www.ossadvocacy.org/docs/oss-school/oss-school.html