questions about GRASS

[Michele Carta]

Dear Sirs, 
I'm a new GRASS user, I've just started using it in a Linux environment.
I have some questions for you. The first one is: how can one import raster
files output from scanners (i.e. in such formats as TIFF, RLC and so on) ?
The second questions is: how can one import 3-d DXF files (I mean, XYZ data) ?
And finally, how can I get the RIM software package ?
I'd greatly appreciate any suggestions on the above.
Gratefully,
Michele Carta

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