A few years ago, when you wanted to use a GNU/Linux distribution for your desktop computer, you still needed to concede a part of your freedom to open some PDF files, run most Java programs, or all Flash animations.
Several steps closer to a fully free system
Right now, the most used version of Java (and therefore, the most targeted by free implementations) is 1.4.2, even though 1.5 has been out for two years now.
With gcc 4, a JVM was added to the existing Java support. Strong with existing free implementations (such as kaffe), this support rapidly reached 75% of compatibility between gcj and Sun's JVM.
Right now it stands at 99.75%.
Thanks to what? Maybe the strong reliance of Openoffice.org 2 upon Java... As a result, a very compatible JVM is now available.
Flash support has always been sporadic under GNU/Linux systems. While it's gotten better with the release of Flash 7 and Flash 9 being developed concurrently for win32, MacOS and GNU/Linux...
Gnash is, right now, the only way for someone using a 64-bit browser to enjoy Flash animations.
And it actually works quite well - its use of OpenGL can even make it a bit more fluid under X.
Adobe and Apple created a very nice format: PostScript, and encapsulated it nicely: Portable Document Format. They went as far as opening the specs on the file format, and provided a readily downloadable viewer for a large variety of platforms.
Ghostscript can now render pretty much every PDF 1.4 file out there.
A full desktop?
I've been complaining about the lack of free 3D support under X; it was time I said something nice about what most people working with computers use everyday...