Maps and models can be imported manually from PC after instalation of package on n900 (just like quake, duke nukem, warcraft2 and other games in maemo repos)

It doesn't matter that hl1 is not opensource when we have quake engine, which is able to open hl1 maps, already working on n900.
(that is the point of this topic )

(Remember that Valve's source engine is based on quake engine. So there is not much difference between quake and hl1)