Qt 4.8.7 Upd May 2026

qmake -project qmake make ./your_app

#include <QApplication> #include <QLabel> int main(int argc, char *argv[]) qt 4.8.7

TEMPLATE = app QT += core gui greaterThan(QT_MAJOR_VERSION, 4): QT += widgets SOURCES += main.cpp Note: QT += widgets is ignored in Qt 4 – keep it for minimal cross-compatibility. | Feature | Qt 4.8.7 | Qt 5/6 | |-----------------------|-------------------------------|-----------------------------| | Widgets module | QtGui | QtWidgets | | QString vs QByteArray | Less efficient Unicode | Better Unicode handling | | OpenGL | QGLWidget | QOpenGLWidget | | Threading | QThread (old style) | Better thread affinity | | Signals/slots | Macro-based (still works) | New syntax (function ptr) | | QML | Qt Quick 1.x (obsolete) | Qt Quick 2.x+ | | Platform plugins | X11, Windows, Cocoa (limited) | Wayland, Direct2D, etc. | 6. Debugging & Common Pitfalls Crash on modern Linux? Qt 4.8.7 uses X11 and older fontconfig. Set: qmake -project qmake make

Add to your ~/.bashrc :

wget https://download.qt.io/official_releases/qtcreator/3.5/3.5.1/qt-creator-opensource-linux-x86_64-3.5.1.run chmod +x qt-creator-opensource-linux-x86_64-3.5.1.run ./qt-creator-opensource-linux-x86_64-3.5.1.run Then set Kit → Qt version → /opt/qt487/bin/qmake . If you're starting a new project → do not use Qt 4.8.7 . Debugging & Common Pitfalls Crash on modern Linux

export PATH=/opt/qt487/bin:$PATH export QTDIR=/opt/qt487 export LD_LIBRARY_PATH=/opt/qt487/lib:$LD_LIBRARY_PATH Use Qt 4.8.7 binary for MinGW (if available) or compile with MSVC 2008 (officially supported). For MinGW: