Which laws work hardest against open source?

Some say patents are the big impediment to open source. Others argue for copyright.

Russell Ossendryver would argue for trademarks.

Unlike copyright and patents, trademarks don't expire. The only requirement is that trademark holders must vigorously defend their marks.

Ossendryver's WorldLabel recently sponsored a contest for Open Office templates and he learned of this first hand. He wrote he had gotten a legal letter from Microsoft, demanding he take a Microsoft Office logo off his contest page. He complied.

The contest ended recently, and the entries "were innovative and brilliant. The winner used hyperlink organization, video graphics, a great demonstration of the versatility of the market. It put the lie to the idea that OpenOffice can't do advanced editing functions."

But Microsoft is not a big problem, Ossendryver said. He has much more trouble from another trademark owner, one in his own niche. This company has even kept him from advertising his product on search engines, saying that if he called himself compatible it would violate their trademark.

"These ads are extremely important," he says. He can only call his products "compatible with brand names" and can't name them. Nor can he buy keywords based on these competitors' names.

Competitors that can't be found by customers don't exist for long. Imagine if PC-compatible computers could not have advertised that fact, 25 years ago. So, is trademark law too powerful?