Ok maybe Public Domain is an oz term
Public Domain = Freeware, the developers gave the product away for free. Never applied for a patent, therefore other parties could step in. Lotus tried to sue MS for using 123 as a basis for excel, and lost heavily.
My Wifes an artist and she gets her ideas ripped off all the time. Next to impossible to claim intellectual property over a pattern........
Yeap leap out with your product, and keep cannabilising it with new releases. That way you get a standard and keep ahead of your competitors. Has worked brilliantly for Microsoft.