why would not SourceGear make diffmerge open source, at least for Linux platforms?

After all, it would be updated, enhanced and Sourcegear could keep the copyright.
Also 64 bits packages could easily be build by ¨open-source geeks¨, for both .deb and .rpm based platforms!
And last but not least, this would advertise broadly the name of SourceGear !
Hope SourceGear just does that, so we could all benefit.
Andre