After you have finished building the basic things from ThirdParty required for SOPE, you can go on building SOPE itself.

As always, please ensure that your GNUstep environment is loaded prior trying to compile anything. A quick check on this is typing echo $GNUSTEP_USER_ROOT, it should point to something like /home/donald/GNUstep and not be empty.

When you are done with SOPE, you can start to build OpenGroupware.org.
Continue at the OpenGroupware.org section.