%general-entities; ]> If you install both Qt4 and Qt5, you can use some simple scripts to select the currently active set of Qt programs. As the root user, create the following scripts: cat > /usr/bin/setqt4 << 'EOF' if [ "x$QT5DIR" != "x/usr" ]; then pathremove $QT5DIR/bin; fi if [ "x$QT4DIR" != "x/usr" ]; then pathprepend $QT4DIR/bin; fi echo $PATH EOF cat > /usr/bin/setqt5 << 'EOF' if [ "x$QT4DIR" != "x/usr" ]; then pathremove $QT4DIR/bin; fi if [ "x$QT5DIR" != "x/usr" ]; then pathprepend $QT5DIR/bin; fi echo $PATH EOF You should now be able to use the appropriate Qt version by running source setqt4 or source setqt5 as desired. (Setting the PATH wont work in a subshell.) Another technique that can be used is to create appropriate alias additions to your ~/.bashrc like alias setqt4='source setqt4'.