However with a growing number of abstractions I built and use all the time, it's becoming a bit hard to 1) share the patches with others and 2) make a kind of snapshot of a project complete with all abstractions used, for example to do easy backups.
I should think this wouldn't be too difficult to do just with a little bash or Python script, even... I guess it would be a convenience for Pd to do it, but I could see it not being too difficult to develop an external program to create "bundles" like this.
As for the actual file format, what about just linking to something like libtar and using already-available routines? For instance, if pd is told to run a file test.tar.gz, it would automatically load the file "test.pd" inside that tar file, and then any abstractions would also assume to be available within that tarball. I guess this wouldn't work so well for externals, however, since the OS couldn't load them from a tarball.
Steve