Qt 4 is a comprehensive, object-oriented development framework that enables development of high-performance, cross-platform rich-client and server-side applications. When you implement a program with Qt, you can run it on the X Window System (Unix/X11), Apple Mac OS X, and Microsoft Windows NT/9x/2000/XP by simply compiling the source code for the platform you want. Qt is the basis for the KDE desktop environment, and is also used in numerous commercial applications. This Qt 4 package is created to enable co-existence with Slackware native Qt 3 package; developers should only remember to use versions with "-qt4" suffix (like "qmake-qt4", "assistant-qt4", "designer-qt4", etc.) of programs that exist under same names in Qt 3 (and developers using CMake should be fine without any additional action, because stock CMake is already looking for "qmake-qt4" first). Qt 4.5 comes with a new graphicssystem backend named "raster" which outperforms the current standard one, but is not yet set as standard because it might not work with all Qt4 applications out there currently. You can set it as standard by passing RASTER=yes to the script. Alternatively you can also set it on runtime for each application (if you start it from the command line). Tests have shown that "normal" Qt4 apps work well with it, whereas KDE 4.2 does not. Further you can enable the patches kde has included in its qt-copy tree by passing QTCOPY=yes to the script. This fixes some issues which make Qt apps nicer to use in kde(4). Descriptions of the individual patches are available in the respective diff or patch files. If you want to additionally *not* build with support for Phonon (as does qt in Slackware-current at the moment), you can pass PHONON=no to the script. WARNING: This requires *a lot* of harddisk space available on build time. Be sure to have at least 2GB of free diskspace. WARNING: Do not use upgradepkg to to upgrade from qt4-4.4.3 or earlier. You should remove the old one and use installpkg for qt4 >= 4.5.0 in that case. If you (accidentally or otherwise) ignore this advice, you can safely remove any broken links in / and rm -rf /usr/lib/qt-4.4.3 afterward :-)