The other problem you'll have is getting a full C/C++ compiler toolchain on the N900 is a tad tricky. It includes enabling the SDK repository and installing some stuff from there.. not to mention having to manually optify some things because of rootfs space.

So realy: C++ development in Maemo is not all that good of an option to be done right inside Maemo (while possible, not realy worth it). However, as I said, all this is available in the easy debian stuff, and would be simpler to setup.

But yes; a Java based IDE would likely run like total trash on such a weak processor in Easy Debian. KDevelop might run a bit smoother.. but none of this is really optimized for touch screens.