Java is not officially supported by Nokia, but see

http://wiki.forum.nokia.com/index.ph..._Java_on_maemo

In principle ANY language can be implemented on the maemo platform, without explicit support from Nokia. This has been done for mono (.net) and Java, perl, etc.

The point is that this makes the most sense for porting existing applications.

Those without a graphical gui (eg Java/Python/.net web apps which can run on a local webserver) require almost no porting effort. Programs with an existing GTK userinterface (Java SWT) can be run on maemo with some effort. It is in principle possible to create bindings to all the maemo APIs for all these languages and this is required if one want to do fancy stuff (multimedia, GPS, device-orientation, etc).

But if one wants to do this fancy stuff, than it is probably not an existing application one wants to port and than it is probably better to write it in C(++) in the first place.

Edit: An interesting development model could be to write eg a Qt frontend for an existing Java backend application. These could be glued together with eg Java JNI or DBUS or ...