Cisco Friday announced it has agreed to acquire two small companies that will help it create a common application development interface for its voice, video and data communications platform.

Bringing together technology from privately-held Metreos and Audium, Cisco will develop a common application development interface for Cisco Unified Communications, according to the San Jose company. Cisco agreed to buy the companies in separate deals, both of which require regulatory approvals and are expected to close in Cisco's fiscal fourth quarter, ending July 29.

Cisco agreed to pay about $28 million in cash for Metreos, a five-year-old company in Austin with 19 employees. It would pay $19.8 million in cash for Audium, which was founded in 1999 and has 26 employees based in New York.

Unified Communications is Cisco's system for bringing voice, videoconferencing, collaboration and other forms of communication together under an IP umbrella, along with policies and online presence capabilities. This area is shaping up as a battleground for many vendors, where what Cisco wants to do may rub up against the plans of Microsoft as well as of other networking companies.

Metreos offers application development and management environments for IP communications. Its technology will help Cisco system integrators, resellers and other partners build applications for the Unified Communications System. Audium provides development and management environments for VoiceXML speech applications. Cisco sees that company's technology helping enterprises build automated voice response systems. Cisco will integrate the two over time to form one application development interface for Unified Communications.

After the acquisitions close, the companies' workforces will be brought in to Cisco's Voice Technology Group.

The IDG News Service is a Network World affiliate.