But do those alternatives offer the same functions as garage.maemo.org?

On the Garage you can also find a lot of websites with information.
like:
http://pc-connectivity.garage.maemo.org/
http://pluthon.garage.maemo.org/2nd_edition/

And what about non-maemo related projects on garage?
i don't know many, but for example:
https://garage.maemo.org/projects/pys60/

It would be nice to keep the current state of Garage accessible, just as a reference.

Also the maemo 5 SDK requires files from:
http://scratchbox.org/
That is also a Nokia sponsored project.