I downloaded xgfe version 2.1 and tried to install it, but got a lot of error messages (unknown header files, unknown data types, ...) and warnings (deprecated headers). I then modified a lot of thing on the source code, before I was able to compile it. The basic functions seem know to work, but the advanced options don't work, because there seems to be a problem with message passing between 2 windows (either because my modifications were (partly) wrong or because I use qt3.3 instead of an older version for which the program was originally built).

Did someone manage to get it work correctly?

It sounds to me like you didn't have all the dependent libraries.
i would read the install notes and make sure you have all the correct dependencies.
It's quite unusual for things not to build properly.

I would say you are missing some library or other.

When I tried to compile it, I got error messages like: strstream.h not found, string is not a type, and so on. Clearly string is a type, and <string> was also included. So I simply added "using namespace std" or changed string to std::string. Or is there an easier way to get things like this to work?

I changed the makefile too. Because I didn't have libqt.a, but libqt-mt.so, I linked against libqt-mt.so (I have qt version 3.3). But I don't think, that this explains most of the compilation errors I encountered. One problem, which may be a cause, why not all things of the compiled program are working, may come from the fact, that on some places a qstring was assigned to a string. g++ didn't accept that, so I changed it, by converting qstring to a string and then assigning it to string. I have to admit, that I don't know qt, and that I don't know, if this can work correctly. Maybe someone, who knows qt well, can answer that.

sounds like you have opened a can of worms