The project named GnuPoc a Symbian SDK for GNU/Linux. What is this? It purports to allow you to develop all your Symbian C++ code on linux. I installed it this week on a fresh debian system. Installation, I have to say, was not exactly trivial. There didn't seem to be any particular HOWTO that covered the Nokia 1.2 SDK very closely. I installed, configured, and built the series60ex/helloworld project finally, got the thing to generate a .sis file, installed it on my 3650 and... nothing. "System Error". That's all. So what gives? I have no idea.
Now I'm starting to wonder if anyone has ever used gnupoc for a 3650 as the target. Seriously. Because all of the recent examples on google are for Sony-Ericsson phones like the p800 and p900. Dunno why that is. But apparently at least one person has used it for 7650, which is basically the same phone as the 3650, so maybe there's some hope.