DiVitas extends call features from PBX (private branch exchange) systems to mobile phones along with integrated instant messaging, presence and location information, and status reporting. The idea is to let workers use one phone and one number both inside and outside the office, with the same features for incoming and outgoing calls. The company has already worked with Nokia and Samsung to get its software on selected Symbian and Windows Mobile devices, respectively. Monday's introduction of the software brings DiVitas to all major enterprise cell-phone platforms.

DiVitas says it offers a more complete set of features on mobile phones than do the two biggest unified communications players, Cisco Systems and Avaya. But all vendors are moving toward making cell phones do the work of desk phones and desktop collaboration, according to analyst Brad Shimmin of Current Analysis.

It was critical to support a range of cell-phone platforms because diversity will be the rule in enterprise mobility, said DiVitas founder and CEO Vivek Khuller. Company-owned cell phones make up a small percentage of workers' devices today, and despite a desire for tighter control by some enterprises, the trend is moving away from them, he said.

"That is a lost game," Khuller said. "'Bring your own device' is the name of the game going forward."

Despite the lure of the much-talked-about application stores for all three of the new platforms, DiVitas went with Web-based software instead. This meant not having to get software approved for any app stores and helped to provide a consistent interface across all the phones, as well as a newly introduced desktop PC client, Khuller said. More importantly, it simplifies maintenance for IT departments, he said. Administrators can define the features on the Web-based interface and control user access to them on an ongoing basis, without having to worry about upgrading software on individual devices.

Ease of deployment and administration is a key advantage of DiVitas' Web-based approach, Shimmin said. However, a native client could provide better access to internal phone resources such as the calendar and contact list, as well as enterprise applications, he said. Eventually, DiVitas may want to go with native software, he said.

"This is a good compromise ... given the level of control and management we have for these devices right now, which is relatively nothing," Shimmin said. He expects a hybrid model to eventually take over, in which employees choose their own phones but allow their employers to install and control software on them in exchange for paying the monthly service bill. Most enterprise IT shops won't fully dictate and deploy workers' phones, he said.