Description of Problem: Firstly, enable KDE's anti-aliased fonts option. You can do this either explicitly in the "look & feel" settings, or by picking a KDE profile which is eye-candy intensive. Restart KDE if required. Edit a text file by sending it to the "Advanced Editor" program. Note how the "Ariosa" font has been used. It is unusable! It is some form of script font and cannot be read easily. This is a very poor default choice. The same problem affects "KEdit". Perhaps this is a generic flaw where some default (fixed width?) font is chosen poorly.
This is because we don't have a fixed width font that can be antialiased (Only Type1 and TrueType fonts can be antialiased), simply because there's no such font out there under a sane license. XFree86 automatically picks the first font it finds (in alphabetic order, that's why it finds Arioso) if it can't find a font matching the original request ("antialiased fixed-width"). This is fixed in Qt 3/KDE 3 [in rawhide] by moving to a sane font abstraction layer rather than depending on X doing the right thing. Until you're ready to upgrade, you may get better results by playing with /etc/X11/XftConfig. Suggested entries to start from: match any family == "fixed" edit antialias =+ "false"; match any family == "courier" edit family += "LuciduxMono";
*** Bug 60271 has been marked as a duplicate of this bug. ***