Backwards compatibility over features

Backwards compatibility over features

That is a disgrace; your experience should be sent to all Free software developers. It is OK to stop adding features if you don't have the time; but it is not good to stop maintaining old stuff. I think we have it backwards most of the time.

However, let us put things in perspective here. Dapper was released in June 2006 and it has been supported for five years. At the time of its introduction Vista had not yet been released (January 2007), so the most current version of Windows was XP (released in October 2001). If your story had read thus:

The system was running in a very old Windows XP PC. When the time came to replace it they first tried with Windows 7; the application refused to run. They called me and I explained what Aero is, and that they needed to install Windows XP Mode, which they did. The application crashed. They had to install an old version of Vista. I don't know what the problem was, just that they could not fix it. After that they have been regretting their decision of buying anything based on Windows.

There are two important differences: first that Microsoft is supporting XP with SP 3 until 2014, and each service pack is essentially a new version of the OS. Second that your client did not pay for Ubuntu, probably. If they had chosen Red Hat they would be happily running RHEL 4 on the new machine (supported until 2015). I think you could do worse than recommending anything based on Red Hat. (Note: I am a happy Debian user, and would be grateful to recommend Debian oldstable; but I also value what Red Hat gives to companies.)