This version focused on "Bug and Performance fixes" but also brought technical innovations that paved the way for Qt 5:
Guide to Downloading and Installing Qt 4.8.0 Qt 4.8.0, released in , was a major milestone for the Qt framework, introducing significant performance improvements and the "Lighthouse" architecture (now known as the Qt Platform Abstraction). While it is now a legacy version and unsupported since 2015 , many developers still require it for maintaining older software or targeting specific vintage hardware. Where to Download Qt 4.8.0 qt 4.8 0 download
Because this version is no longer the current release, it is found in the official Qt Download Archives. This version focused on "Bug and Performance fixes"