In 2007, the Nokia N800 came out. Nokia released Maemo OS 2007, and dropped support for the N770 they had been selling a few months before. The OS2008 / Maemo 4 release wasn’t released for the N770 by Nokia, though hackers released an unofficial distribution.
Next came a point release, which was a major pain to install, but added APT support so that the OS could be updated without having to mess with firmware tools. Nokia promised that this would be the last time we’d need to flash the OS.
That was true, in a way, because in 2009 the N900 came out running Maemo 5, and Nokia dropped all support for the N800 and N810. They announced that Maemo 5 wouldn’t run on those devices.
Pretty much as soon as the N900 was released, Nokia bought Trolltech, and announced that Maemo’s GTK UI was a dead end–future devices would run Qt instead, via a different Linux based on merging Maemo with Intel’s Moblin. The new OS would be called MeeGo.
Now they’ve announced that the N900 hardware is a dead end too–it won’t run MeeGo when it’s launched later this year, you’ll need to buy another new device for that. (Again, though, there may be a hacker version.) Nokia are also throwing away APT in favor of the craptastic combination of RPM and yum.
There are probably people in Nokia who are wondering why Android is exploding in popularity, while their smartphone efforts are even less popular than Windows Mobile.