OpenFeint has been working on its OpenFeintX - now rebranded OFX - freemium and in-app purchase platform for six months or so.

Now however, it's officially released the technology with a promotional revenue waive scheme.

The OFX Freemium Challenge will reward the first 100 games launched using the technology each to $10,000 of free IAP sales before the official revenue share business model kicks into action.

OFX is free for game developers to download and implement, with OpenFeint taking a cut of paid downloadable content in those games.

In the cloud so you don't have to

It's based on a set of client and cloud-based services that help developers sell new content in their games without having to submit full updates to Apple. Future updates will allow you to offer virtual currency and virtual goods for sale.

"With OFX, OpenFeint offers a service that allows us to forgo building and maintaining a server to deliver downloadable content," said Andy Coates of True Axis, creators of Jet Car Stunts.

"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."

"We've decided to use OFX because it provided us with the most streamlined way to build freemium titles without infrastructure costs," agreed Shainiel Deo of Halfbrick Studios (Fruit Ninja/Monster Dash).

"We would much rather focus on building great games and leave the server technology to the OpenFeint experts."

Spanner to their wallet

"With the OFX Freemium Challenge, developers will see how easy-to-use and profitable OFX can be in their games with little commitment," said Jason Citron, OpenFeint's CEO.

"We've all seen that the freemium model is generating some amazing results. OFX gives developers the tools they need to take advantage of this emerging model."

You can find out more from the OpenFeint website.