I know that there were some changes in this filed with the introduction of TQt with already translated Q* objects to QT*. But I have I noticed on my system another thing having both qt3.3.8d and qt4.8.0 installed and I don't know if there are movements to resolve this. Qt provides set of tools that enable creation of qt-based applications. Those are: assistant, designer, linguist , lrelease, lupdate, moc, qmake, qtconfig, uic. Those are provided both by qt4 and our qt3. If I have both of the qt versions installed and I try to run one of those applications, only the qt4 versions are launched, and I am unable to launch qt3 ones unless i specify full path to them as command. That may be because I installed qt4 as second, and if I were to install it first and then qt3 then I'd be able to start only those provided by qt3. If I run those commands through whereis I get: assistant: /usr/bin/assistant /opt/qt/bin/assistant designer: /usr/bin/designer /opt/qt/bin/designer linguist: /usr/bin/linguist /opt/qt/bin/linguist lrelease: /usr/bin/lrelease /opt/qt/bin/lrelease lupdate: /usr/bin/lupdate /opt/qt/bin/lupdate moc: /usr/bin/moc /opt/qt/bin/moc qmake: /usr/bin/qmake /opt/qt/bin/qmake qtconfig: /usr/bin/qtconfig /opt/qt/bin/qtconfig Obviously, if I invoke assistant, the first path is executed. As a temporary solution for my packages I create links to the qt3 tools in $prefix/bin/ and name them in the Qt3* scheme. Anyway I think those should be renamed in the TQt3 to avoid collisions with Qt4 ones.