It’s been quite some time since we first heard about OpenFeint’s freemium strategy, OpenFeint X. Now going under the new moniker of OFX, the program has finally launched, and OpenFeint is enticing developers to try out their brand of downloadable content by announcing the $1 Million OFX Freemium Challenge.

The OFX program is aiming to do the same thing for in-game purchases that the OpenFeint network managed to do for the social experience: provide developers with a free set of tools to implement important features without the cost and headache of managing these elements themselves.

Halfbrick Studios, makers of the games Fruit Ninja, Monster Dash, and Age of Zombies, will be among the first to use the OFX system. “We’ve decided to use OFX because it provided us with the most streamlined way to build freemium titles without infrastructure costs,” says Shainiel Deo of Halfbrick Studios. “We would much rather focus on building great games and leave the server technology to the OpenFeint experts.”

Other notable developers have signed on, too. True Axis, the team responsible for the immensely popular Jet Car Stunts, piloted the OFX program by using it to sell level packs in game prior to OFX’s formal release;

“With OFX, OpenFeint offers a service that allows us to forgo building and maintaining a server to deliver downloadable content,” says Andy Coates of True Axis. “By just adding a few dozen lines of code into the project, we had a mechanism in place for people to use in-app purchases and download data from the OpenFeint servers. We saved months of time by using this service.”

While the OFX implementation will be free, developers will need to participate in a revenue sharing program with OpenFeint for any content they manage to sell. The $1 Million OFX Freemium Challenge, however, is designed to encourage developers to try their services without initially having to give up a portion of their sales. For the first 100 games that go live with OFX, developers will be allowed to make $10,000 in downloadable content sales before revenue sharing kicks in.

Developers interested in learning more about OFX and the $1 million Freemium Challenge should visit the OpenFeint Developer website.