VMware is acquiring Gemstone, a Beaverton, Or.-based company that develops real-time caching and distributed database technologies that serves as an in-memory data fabric for masive data processing and transaction environments.

The technology is used as middleware for SpringSource, the platform VMware acquired recently. SpringSource is the foundation for VMforce, the Java-based application development platform it launched with Salesforce.com last week.

Gemstone represents that data fabric for VMware. It provides the capability to develop read/write applications. This comes from Gemstone's ability to transact massive data sets.

That's a critical aspect of the VMforce platform. Apps need to have that interaction capability. It's the key aspect of the VMforce service in the capability to create micro-applications for any number of enterprise uses.

Gemstone has historically worked with large companies in financial services, for instance, that require big data, real-time transaction environments.

Terms of the deal were not disclosed.