Qt is also used in the open source community and is the basis for the KDE desktop environment for Linux. The technology is used by Motorola as the basis of its Linux mobile phone platform.
Nokia said that it will acquire all of Trolltech's software assets and personnel, and that Qt/Qtopia will become a "pivotal part" of Nokia's software strategy.
"The acquisition of Trolltech will enable Nokia to accelerate its cross-platform software strategy for mobile devices and desktop applications, and develop its internet services business," the firm said in a statement.
"With Trolltech, Nokia and third-party developers will be able to develop applications that work on the internet, across Nokia's device portfolio and on PCs.
"Nokia's software strategy for devices is based on cross-platform development environments, or layers of software that run across operating systems, enabling the development of applications across the Nokia device range."
Examples of current cross-platform layers are Flash, Java and Open C.
Adam Leach, senior analyst at Ovum, said: " From the perspective of Nokia's push into internet services via Ovi the acquisition of Trolltech makes perfect sense.
"Nokia has asserted from the start that Ovi will enable services across a number of platforms including web, PC and mobile-based platforms.
"Trolltech has proven technology in cross-platform development and there is a good synergy here for Nokia."
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