Nokia has offered to buy Trolltech, the Norwegian developer of a widely used application framework, for 844 million Norwegian kroner ($153 million) in cash. Nokia hopes the Trolltech development team will give its own software efforts a boost.

Trolltech develops Qtopia, a framework used to build user interfaces for mobile and embedded devices, and Qt, a cross-platform application development framework.

Nokia hopes to use Trolltech's expertise to improve the interfaces on its S40 mobile phone and S60 smartphone platforms, but Trolltech targets many software platforms with its application frameworks.

In 2006, Samsung unveiled a reference design for a mobile phone running Qtopia Phone Edition on top of a Linux operating system. And the Trolltech team has been working since late 2006 on a version of Qt for Microsoft's Windows CE and Windows Mobile platforms.

Qt can also be found in a variety of widely used desktop software, including Skype's Internet telephony application, the Google Earth satellite photo browser, and Adobe Photoshop Album, now part of the Photoshop Elements image editor, according to Trolltech.

The framework is available under commercial and open source licenses; it is also used by the developers of KDE, a desktop environment for Linux operating systems. Trolltech recently updated the licensing conditions for Qt, making the code available under the GPLv3 license in addition to the GPLv2 license it already uses.

The Trolltech team will become part of Nokia's research and development group, where it plans to continue its work with the developers of KDE.

Despite the close relationship Nokia will now have with the developers of KDE, the company will continue to use a rival software platform in its Linux-based N800 and N810 mobile Internet devices.

"Our platform for Internet tablets will continue to be based on the Gnome environment," said Kai Öistämö, Nokia's executive vice president for devices.

However, Nokia will use Qt in its S40 and S60 platforms, Öistämö said. He would not say when phones containing the code will reach the market.

Nokia has pledged to continue offering commercial and open source licenses for Qt and other Trolltech products as it continues their future development.

The two companies expect to complete the acquisition in the second quarter. The deal requires the approval of holders of 90 percent of Trolltech's shares. Nokia already has support from the holders of 66 percent of the shares, it said.