I actually was browsing around the documentation of maemo's overall layout and from what i've seen, Hildon is actually built on Gnome moble, witch is obviously whi most applications in maemo are gtk based and whi it uses matchbox as it's basic framework.
If you look at Gnome moble and Hildon, you can allmost edmeditly know whi thay include the N800 as a device that uses Gnome moble... Because.. basicly... If i am correct, Hildon is a form of Gnome moble that Nokia re-named and implimented into maemo. Their are a lot of similaritys between Gnome moble and Hildon.