Adobe is using Alfresco’s open source ECM software as the file repository in Acrobat.com, a set of free online services – file sharing and storage, PDF conversion, online word processing and web conferencing – that can be used to create and share documents, communicate in real-time, and simplify collaboration within and between organizations and individuals.

We’re talking millions of documents and terabytes of data here.

Millions of users are supposed to have free access to Acrobat.com’s file-sharing capability directly from Adobe Reader.

The news builds on the existing Alfresco/Adobe OEM relationship on Adobe LiveCycle.

Alfresco claims the latest development validates the idea that open source software and Alfresco are proven for the enterprise.

Adobe reportedly chose Alfresco for its clustered high-availability, security and technical support.

Erik Larson, director of marketing and product management for Acrobat.com, said, “Alfresco’s feature set accelerated our ability to bring Acrobat.com to market.”

Alfresco CEO John Powell claims, “We have helped commoditize and consumerize content management, making it easy to embed into hosted and enterprise applications with next-generation RIA interfaces, such as Acrobat.com or Adobe LiveCycle.”

The Acrobat.com beta is at www.acrobat.com.