The tools we'll mention here are designed to port apps from
OpenStep to GNUstep. But, as a matter of fact, they go much
further since they will allow you to port Mac OS X apps
as well. That's the important point : more on this later !
First, there's a tool called OpenStep2GNUConverter, allowing
you to convert a PBProject (Project Builder) to a GNUstep
Makefile. That is, you'll be able to compile an OpenStep project
on your Linux box (for instance) . To compile this project,
you'll need another tool called nfmake. A tool called nib2gmodel
allows to convert a nib file (produced with Interface Builder)
to its equivalent under GNUstep, named gmodel.