.. _glossary: ******** Glossary ******** .. glossary:: AGG The Anti-Grain Geometry (`Agg `_) rendering engine, capable of rendering high-quality images Cairo The `Cairo graphics `_ engine FreeType `FreeType `_ is a font rasterization library used by matplotlib which supports TrueType, Type 1, and OpenType fonts. GTK The GIMP Toolkit (`GTK `_) graphical user interface library PyGObject `PyGObject `_ provides Python wrappers for the :term:`GTK` widgets library pyqt `pyqt `_ provides python wrappers for the :term:`Qt` widgets library and is required by the matplotlib Qt5Agg and Qt4Agg backends. Widely used on linux and windows; many linux distributions package this as 'python-qt5' or 'python-qt4'. Qt `Qt `__ is a cross-platform application framework for desktop and embedded development. Qt4 `Qt4 `__ is the previous, but most widely used, version of Qt cross-platform application framework for desktop and embedded development. Qt5 `Qt5 `__ is the current version of Qt cross-platform application framework for desktop and embedded development. Tk `Tk `_ is a graphical user interface for Tcl and many other dynamic languages. It can produce rich, native applications that run unchanged across Windows, Mac OS X, Linux and more. wxpython `wxpython `_ provides python wrappers for the :term:`wxWidgets` library for use with the WX and WXAgg backends. Widely used on linux, OS-X and windows, it is often packaged by linux distributions as 'python-wxgtk' wxWidgets `WX `_ is cross-platform GUI and tools library for GTK, MS Windows, and MacOS. It uses native widgets for each operating system, so applications will have the look-and-feel that users on that operating system expect.