Installing apps under most distributions is rather simple. When it's not simple, though, it becomes a lot more difficult. Easy is dead easy. Everything else is pretty difficult.
There are five classes of applications:
- Apps in the distribution's repository. Installation is dead easy, but unless you are on a rolling-release like Debian Testing or Arch, your package versions are fixed. That's where Michael Horowitz hit his glitch -- he wanted a different version. Most long-time Linux users don't think about this part and just assume they'll get the newer version when they update. Six-month distros like Ubuntu and Fedora make the wait bearable.
- Apps packaged for the distribution but not in the distro's repo. Skype comes to mind here, and GetDeb is similar. There are no external dependencies, and a user can just download and install the package. GDebi makes this a "double-click" affair. This is probably the most comfortable for Windows users, but is still harder than #1.
- Apps packaged for the distribution that require additional dependencies outside the base repositories. Newer versions of software often fit here. If someone wants the latest version of Elisa, that's going to include some Python upgrades and maybe GStreamer, too. This generally requires adding a repository, and the process is kind of scary for non-techies. Ubuntu has had a blueprint since Hardy for a one-click repo add using whitelists, but it hasn't actually happened yet. Adding outside repos is also a good way to screw up your machine now or during an upgrade.
- Apps not packaged for your distro, either in tarballs or with special installers. These are difficult to get for newbies and almost always involve four or five command line operations. It's also pretty easy to hose your system if you don't know what you're doing and put stuff in the wrong place, accidentally writing over system libraries.
- Apps not designed for your system. Windows programs are the best example of this class. While some programs work well, and some work (but not well), I prefer to tell people in this situation to expect that programs won't work under Wine until proven wrong. I have a website of no-config tested games (most using Wine) for just this purpose.
Still, Michael Horowitz was being disingenuous and probably trolling, as he refused to accept much of the great advice that was given to him in the comments, preferring to compain about the difficulty involved. Oh, and Firefox on Ubuntu 8.10 isn't "buggy and out-of-date." He won't seem to accept that, either.