The Chalkbot, a one-ton wonder of artistry and machinery and telecommunications, was the hit of the Tour de France. But its ideological roots as a robotic symbol of protest has led to charges its Pittsburgh creators have sold out to a corporate giant -- and sold out their one-time technical collaborators, too.

In the Internet row piqued by the Chalkbot's debut, tech experts have weighed in on issues of collaborative design, open-source programming and even patent law. As online stirs go, it's a small one, yet it provides insight into how small tech and art collaboratives view themselves and view those who would profit from their vision.

The Chalkbot is a truck-towed robot that sprays chalk messages on pavement. It is interactive, accepting text messages from cell phone users and then translating the messages into chalk writing.

And, as you may have heard, it was designed in Pittsburgh.

The Chalkbot went public last month at the Tour de France, spraying inspirational chalk messages and occasional wedding proposals along the race route, part of Lance Armstrong's "Livestrong" cancer-research campaign.

"We built Chalkbot, together, so that people from everywhere can spread messages of hope and cancer survival to the entire world at the Tour de France," said Nathan Martin, CEO of Deeplocal, in a promotional video explaining creation of the robot. (Deeplocal, an East Liberty Web and software design firm, designed the Post-Gazette's Web site, post-gazette.com.)

Deeplocal drew up the Chalkbot with Standard Robot, a one-man custom robotics company headquartered Downtown. Deeplocal compiled the chalk-writing software and Standard Robot built the actual Chalkbot.

The two Pittsburgh companies retain the intellectual property behind the robot's design, and are investigating whether that will be patented or kept as a trade secret.

But Nike now owns the Chalkbot itself. Deeplocal and Standard Robot sold the Chalkbot to Nike for an undisclosed sum after Nike advertising agency Wieden+Kennedy approached Deeplocal three months ago, asking it to complete the project in time for the annual cycling race. The robot is being transported back to Nike's campus in Oregon, where it might be used in future races or marathons.

So we know who owns the intelligence behind the robot. But who invented the Chalkbot?

Soon after the device started getting some publicity, a group called the Institute for Applied Autonomy issued a news release, saying: "This week Nike unveiled a cool 'new' chalk-writing robot used to print messages on the road during the Tour de France bicycle race. The trouble is, the robot isn't so new after all. The Nike Chalkbot is nearly identical to the 'Streetwriter' we began developing 10 years ago."

The IAA's Streetwriter and the smaller GraffitiWriter were used to write "politically controversial messages in six countries, and major cities." Often the messages protested the military use of robots.

"We do not claim any sort of ownership over the [Chalkbot]. ... While we have long expected our anti-corporate project to one day be reappropriated as an advertising scheme, we are surprised that in this case, the culprits are close associates," the IAA release said.

Mr. Martin and Greg Baltus, the man crew behind Standard Robot, are the "associates" and "culprits" in this case.

"What's sad to me about all that is a lot of the people involved in all that were my personal friends at one point," said Mr. Martin. He also said the IAA is overstating the relationship between the Chalkbot and the earlier devices.

"Technically, there's almost no similarity," said Mr. Martin. "As an idea and inspiration for later work? Of course."

But even if there were great similarities between the Chalkbot and Streetwriter, the man who engineered the Chalkbot, Mr. Baltus, is the same man who helped design Streetwriter.

"The only thing [Chalkbot] had to do with [Streetwriter] was the general idea of printing on the road," Mr. Baltus said. "It was all new code. It was all new mechanical systems."

The Institute for Applied Autonomy is an official-sounding outfit but, like Deeplocal and Standard Robot, it's a small operation with Carnegie Mellon University roots. Richard Pell, a filmmaker and an art professor at CMU, is one of the founding members of the IAA and describes the group as an "art and engineering collective."

Mr. Pell and Mr. Baltus crossed paths at IAA, before Mr. Baltus formed his own firm.

The IAA's chief complaint is that Mr. Martin and Mr. Baltus took what had been a collaborative project and made it theirs. The IAA responded to questions via e-mail.

"Why Nathan and Greg then chose to keep this a secret from us is the real mystery. Had [they] simply contacted us about this project beforehand, we would have discussed it collectively and could have helped him find amicable ways to give attribution to the anti-commercial origins of the work that he has now commercialized.

"All of our work has always been given freely, but attribution, particularly by close associates is expected. ... When given the choice, Nathan opted to honor a contractual agreement with a public relations firm rather than to honor the many years of collective artistic work that he claims has been such an inspiration to him."

Mr. Baltus sees it differently.

"We all worked together on different projects" in IAA, he said. "And we all used those experiences in our careers in different ways. ... This is one of the difficulties of working as an art group. If you want to make the claim that something is being stolen from you, [then] you have to be a legal entity, you have to patent your work."

Mr. Martin also suspects that some of the chafing is caused by Chalkbot's buyer. Nike is a huge company that's easy for anti-corporate types to hate.

"Nike's always a big target to people," he said.