
Whenever I use KDE, the part I dislike the most is the rendering engine used by Konqueror, called KHTML. KHTML just doesn't render pages as smooth and as well as Gecko and the KHTML fork WebKit, up to a point where I find Konqueror unusable as a web browser. However, work is underway to replace KHTML in Konqueror with WebKit, but according to KDE developer Adam Treat, this is a futile effort:
Konqueror is too KHTML API specific.