I'd like to use my webserver to download
and compile stuff for me (like Ambient )
since I'm on a slow ISDN-connection and dont
want to download too much.

I found the crosscompiler site, downloaded the
MOS-DevKit-Files but I've no clue what files I
need from it and how to set it up.
Do I need the amiga includes ?

http://www.lysator.liu.se/~lcs/files/gg-cross/

So far I've a directory like this

gg-ppc-morphos-binutils-2.9.1-4.i386.rpm
gg-ppc-morphos-gcc-2.95.3-5.i386.rpm
gg-ppc-morphos-ixemul-devel-49.0-1.i386.rpm
gg-ppc-morphos-libdebug-devel-1.0-1.i386.rpm
gg-ppc-morphos-libnix-devel-2.0-8.i386.rpm
gg-sfdc-1.3-1.i386.rpm
gg-texinfo-4.6-1.i386.rpm
mossdk_devenv.lha
mossdk_devenv_includes.lha

Is there somewhere a step-by-step manual ?

I didn't try to use these packages but i played with cross-compiling in general. So here are some generic principes of installing a cross compiler:
1. Install compiler binaries. This will give you:
- /usr/bin/ppc-morphos-gcc and friends;
- /usr/lib/gcc-lib/ppc-morphos - internal gcc's stuff.
- /usr/ppc-morphos - the most important place.
2. Next, you need includes and linker libs for your target system. You need to extract them from an SDK and place in the following places:
- /usr/ppc-morphos/include - includes. In case of MorphOS SDK you'll need to merge include and os-include directories and put here their contents. include-std is not needed at all (i wonder why it's there) because it duplicates "include" contents.
- /usr/ppc-morphos/lib - place here all linklibs (everything which normally resides in /gg/lib in native anvironment).
Then it should work. At least i have m68k-linux crosscompiler on my Pegasos box (self-built one) and it works this way.

Thanks Sonic

The rpms default to /opt/gg as path and I dont want to change
it but I guess thats ok

I've added the missing common rpms and extracted the SDK.
I've copied from the SDK
MorphOS SDK/InstallData/DevEnv/support/gg_tree # cp -r ./ /opt/gg

And from my local gg-install I've copied the amiga-includes
with cp -r amigaos /opt/gg/os-include

What I dont know is f.e. what are the SFD-Files mentioned
in the section "Include files" ?