This is not the first name change. Trolltech, which was acquired by Nokia in June last year, was renamed Qt Software in October last year. The new name better matches Nokia's strategic vision for Qt.
Going forward, Qt will play an ever increasing role in the future of Nokia's key mobile software platforms. It's also as a development framework on multiple other software platforms. The front page of the Qt site currently features examples and quotes from multiple products and vendors.
Daniel Kihlberg, director of global sales, marketing, and services for Nokia, Qt Development Frameworks, explained the rationale behind the selection of the name and domain, "We want to increase the use of Qt by mobile developers and to achieve this we've strengthened our name's link to the Nokia brand. The progress of our new Qt for S60 product and our future involvement in Maemo are examples of how Qt will reach out to mobile developers in addition to desktop and web developers."
"We selected Qt Development Frameworks because at the end of the day, our goal is to provide developers with the best framework: Qt."
Twitter users may like to note the general Qt account has changed to @qtbynokia.