Any Software Engineer will tell you open source projects are at the cutting edge... They are the projects that use the latest technology and most efficient code to bring about new processes. I think that is part of the reason why Linux is so popular. C++, Java, JSP, and PHP are all pretty cutting edge programming languages, but .NET is so much easier.
Apple and Microsoft, since they are all about profit, direct their resources to building very user friendly application that compartmentalize processes that before would have taken a long time to code. Basically making the end-user happy. Open Source on the other hand makes the user, developer, happy, but because it isn't focused on the end-user, it may be harder to use. Of course coders all b!7ch and complain about Microsoft until they want to hire us. 😉