The controversy over the government programs led to a tense session in a packed ballroom at the Hackers on Planet Earth conference this summer in New York, where recipients and critics of the Darpa financing gathered to discuss its implications.

“If you grow a piece of celery in red water, it’s going to be red,” said Sean Auriti, who is known as Psytek at the hackerspace Alpha One Labs in Brooklyn, which he runs. “I’m just wondering how this Darpa defense contract money is going to influence these projects.”

And yet Mr. Auriti himself is benefiting from the Darpa money as a member of SpaceGambit, a consortium of hackerspaces that won a $500,000 grant for research in space exploration and colonization technologies. He said he hoped that the grant would help him build a mini-thruster to launch backpack-size satellites into orbit.

But the debate over the financing has prompted him to establish a separate working group for the space research with Darpa. That way, none of his workshop’s members will feel as though they are unwillingly participating in government work, he said.

Some on the conference panel voiced concerns that Darpa financing would steer more hackers toward military projects. Mr. Altman, the Noisebridge co-founder, said he viewed the influence of military money as a threat because it would lead hackers to choose projects that might appeal to grant makers, as opposed to following their passions, however idiosyncratic.

Everyone on the panel agreed that hackerspaces could provide an exciting model for hands-on technical education in schools, and Dale Dougherty, the founder of Maker Media, which caters to the do-it-yourself movement, said he believed that the high school program that his company was managing would do just that.