The latest 4.8.0 release has a number of major features, most important among them being Qt Platform Abstraction (QPA).
For those who don't know, Qt is a cross-platform framework for developing applications. It is heavily used by the KDE Plasma Workspaces and other KDE software and is also in use in popular software such as Autodesk Maya, and the VLC media player. It is also used in the recently revamped version of the Tweetdeck client.
The latest 4.8.0 release has a number of major features, most important among them being Qt Platform Abstraction (QPA). Qt is already quite well ported and available for many platforms, however this feature, originally code-named 'Lighthouse,' makes Qt a lot more portable. QPA simplifies the process of creating ports of Qt to new platforms, so it can easily be used with embedded hardware that might not be running standard operating systems and window managers.
Other than Qt Platform Abstraction, Qt also comes with he following features (according to the release post):
Enables those of us that are not OpenGL-ninjas to render OpenGL from more than one thread concurrently.
HTTP requests are now handled in a separate thread by default. This should make application guis smoother, as networking will no longer use the main event loop.
The file system stack received some heavy lifting under the hood. The result is better I/O performance, achieved by reducing the number of system calls performed for I/O and by better use of cached data, when available. The improvements in performance can be seen across all platforms.
You can download the latest version of Qt and its developer tools from here.