Neither the openSUSE 10.2 CDs nor the DVD image contain the the gcc-obj or the libobjc packages required to compile and run Objective-C applications such as OpenGroupware. I'm led to believe that the commercial DVD does contain more packages as it is multi-layered.
Fortunately this oversight is easily remedied; you just need to add the online package repository as an installation source. Go into YaST / Software / Installation Source, then add an HTTP source with a "Server Name" of "download.opensuse.org/distribution/10.2/repo/oss/". This is the default package repository for all Open Source packages provided with openSUSE 10.2. Clicking "Next" will then cause YaST to thrash around for awhile as it downloads what it needs to support the installation source. After prompting for acceptance of the same license agreement you accepted when installing the distribution the channel should be available.
Searching in Software / Software Management you should now find three Objective-C related packages: gcc41-objc, gcc-obj, and libobjc41. Only the latter is required to run Objective-C applications.
Once libobjc41 is installed then the OpenGroupware packages for OpenSuSE 10.0 will install and run.