Apprenda, the open Platform as a Service (PaaS) stack provider, has released version 3.0 of its free platform offering, Apprenda Express. The free PaaS solution is now fully-functional, something that Apprenda CEO Sinclair Schuller said that customers had been requesting.

“Our free program has always been available,” Schuller said. “But some of the functions were limited and people have been pushing us to open other capabilities.”

The Apprenda Express 3.0 release unlocks all of the in-demand capabilities free users have long been looking for: application billing, deploying more than three servers, and access to Apprenda’s plug-in extension. The only limitation now is size, as Apprenda Express customers can use up to a 12 gigabyte platform. Once they exceed those 12 gigabytes, they have to buy an Apprenda license and pay a fixed price for each additional gigabyte.

“Getting the technology in people’s hands is the key here,” Schuller said when explaining the company’s expansion of its free Apprenda Express product. “This is a great marketing move for us.”

Remember that Apprenda Express 3.0 still comes with all of the same out-of-the-box architectural components and application services as the full paid version of Apprenda. Those components include application management tools, frameworks and APIs, and a run-time model that lies underneath user applications.

Wondering how Apprenda plans to bring in revenue if it’s expanding its free services? The company has other .NET cloud middleware solutions like its Apprenda application server that it paired with Tenzing Managed IT Services‘ EVEREST Infrastructure as a Service (IaaS) platform through a strategic partnership with Tenzing back in December 2010.