Combined, the Fonav and Qtopia software will enable a presence-based in-box for calls, email, instant messaging and voice messages. The address book will also have presence, which means users can control how and when they wish to reach others.

The so-called Unified Communications Platform could be used in cell phones and VoIP devices, Trolltech said. As such, Norway-based Trolltech said it would create new revenue for service providers, including broadband and VoIP operators, wire-line operators and web portals.

The software is SIP-based and includes VoIP services for calls made to and received from any number. Instant messaging uses the Jabber XMPP protocol, which enables users to communicate using text or voice with open communities such as Google Talk, Trolltech said. Email includes POP3 and IMAP access.

Fonav, which founded in early 2006, said all its employees would join Trolltech’s Redwood City, California office.