I'm wondering if it's safe to add Debian/ARM repos to Maemo (N900).

There are a lot of packages I'd like to be able to use (e.g. screen, and a number of X11 apps out there) if I could, but I don't want to trash everything that's there already in Maemo.

Would it be possible to do this? Should I set pin priority for Nokia packages?

I've installed a couple of Debian armel packages and worked like a charm :-)

I don't recomend adding the Debian repos because that would mix alot of packages. Just go to http://packages.debian.org , find the package and download it! Then install with dpkg -i package.deb

Be careful most of packages not optified there....
And they will use most important memory on "/"

some packages can be updated, you will get a firmware-update-notification when you remove mp-fremantle-generic-pr. The device will work normally, but some applications can have a strange behavior with updated packages, and some updates will temp. brick your device.

I was able to install (without bricking) via apt-get: Kile, Inkscape, Dia, Audacity, Mousepad, pcmanfm, Blender, Netbeans and dependencies.

There is one thing I don't understand:
If I try to install anything from the Debian repo, it wants to remove fremantle-generic-pr.
But why?

installing .debs from the debian arm repository directly in maemo is not such a good idea IMO.

better try Easy Debian.
with this chroot environment, you get full and easy access to the Debian ARM repo, with apt-get / synaptic and everything.
since this is inside an image file (which resides on MyDocs), you don't have to worry about optification or package dependencies, because they get resolved automatically.
also, packages like libc and so on are in a current version, not the "older" versions that get shipped with Maemo, and which could cause trouble if you --force the installation of a package.

Netbeans and dependencies? How did you get Java JDK and netbeans to install? Since they are huge packages, didn't they fill the rootfs? Did you repackage them to be optified? Did you recompile them?

Okay... but could you tell me why does it want to remove "fremantle-generic-pr"?

that's the package for the root filesystem. it has many very specific dependencies, all of them refer to a specific version number (not "at least" a certain version, but "equal to").

the packages in the debian arm repo have been compiled with newer components, so every package from there which needs a certain software product with a higher version number will break the dependencies of the rootfs-package.

put simpler, a debian arm package will depend on some library with a version higher than what Maemo offers. the installer will try to solve that dependency by installing the library with the required number, but because fremantle-generic-mp requires the specific version that is currently installed, the installer cannot update that library without deinstalling fremantle-generic-mp first.

needless to say, deinstalling fremantle-generic-mp is _not_ recommended.

none of that is a problem under Easy Debian btw, because inside that chroot all the libraries are already up-to-date, or can be updated without much hassle.

Thanks for explaining!
This is very weird. It reminds me of the "DLL hell" we had on Windows 98...

However, now on Windows the different versions of most of the applications and libraries can coexist without any issue. (For exaple, you can have all versions of the .NET Framework installed, even the newest beta, without them disturbing each other.)

Isn't it possible on Linux?

Or otherwise, why don't they update the dependencies of the fremantle-generic-pr, so everyone could be happy?