Well, I 'installed' lilypond on N900. It segfaults. No surprise, I 'installed' lilypond and lilypond-data from Debian-Lenny, ignoring that libc6 on Maemo-5-Fremantle is out-of-date, and disregarding tex-dependencies because I am out of RootFS space.
I already uninstalled adobe-flashplayer. It's possible, though highly unlikely, that I will uninstall binutils and g++ from N900 in near future - it's mostly used for rare experiments. However, I would rather find out a way to optify them, and perl, too.
Best wishes.