Many free software projects have, among other characteristics, punny project names. Some notable examples:
- GNU CSSC (Compatibly Stupid Source Control), a clone of the Unix source control system SCCS (Source Code Control System).
- GPG (GNU Privacy Guard), a clone of Phil Zimmerman's encryption program PGP (Pretty Good Privacy)
I suspect that people would think twice about choosing those names if those products were invented today. Naming a similar product (a clone, even) with a name that is intentionally confusingly similar seems, indeed, like the perfect way to get yourself slapped with a trademark lawsuit. (After all, it happened to Lindows.)
At least GNU is safe. No reasonable person would think that GNU's Not Unix was the same as Unix.