In a posting on the Sourceforge.net site, Douglas E. Warner said he received a letter from an attorney representing AOL, who asked him to stop using the letters "AIM" to describe his phpAIM project. PhpAIM is an interface to AOL Instant Messenger written in the open-source PHP language.
Trademark holders often send out dozens, if not hundreds, of letters to a wide variety of people they feel are violating their trademarks--parties ranging from journalists, to competitors, to inventors--in the hopes of getting them to stop using a particular word.
AOL spokesman Andrew Weinstein would not say how many letters AOL has issued relating to its AIM trademark, but he said the action against Warner was not unusual. "We regularly take action to protect our trademarks and intellectual property," he said.
In addition to asserting trademark claims, the AOL letter warned Warner that he was not authorized to distribute an AIM-compatible product.
"The proprietary software used to operate the AIM service is owned solely by AOL, and unauthorized distribution of our client's software, or derivatives thereof, is strictly prohibited," the letter said.
Warner did not immediately respond to requests for comment.
AOL has long refused to open AIM to competitors and has blocked companies, including Microsoft, from making their IM products compatible with it. AOL says it is working on ways to open the service, but it has not revealed a deadline for doing so.
A recent domain name victory may have emboldened the company to go after more people who use the word "AIM" in their products. Last month, AOL won the rights to the names Aimster.com, A1mster.com, Aimstertv.com and Aimstertv.net, after a National Arbitration Forum board ruled the sites violated the AIM trademark. The ruling could pull the site out from under Aimster, a wildly popular service that combines file swapping with IM features. However, the case is on appeal, and the site is still under Aimster control.