There is also Turkish government funded Pardus project [0] and has been going on since 2005. Numerous government institutions started to use it but still not enough to ditch Windows.
What interested me most is that Pardus project had its own packaged manager called PiSi, which was then adopted by Solus.
I bet Pardus project had their own reasons to adopt the apt system and rely on Debian volunteers for all packaging support. As the OS is largely maintained by a government institution, I'd imagine it doesn't have the large userbase as Debian does.
There are also some other cool projects made for Pardus, for example Zemberek, a spell checker for the Turkish language that uses natural language processing for Libreoffice and Openoffice: https://github.com/ahmetaa/zemberek-nlp