PyQt is a Python binding of the cross-platform GUI toolkit Qt, implemented as a Python plug-in. PyQt is free software developed by the British firm Riverbank Computing. It is available under similar terms to Qt versions older than 4.5; this means a variety of licenses including GNU General Public License (GPL) and commercial license, but not the GNU Lesser General Public License (LGPL). PyQt supports Microsoft Windows as well as various flavours of UNIX, including Linux and MacOS (or Darwin). PyQt implements around 440 classes and over 6,000 functions and methods including: a substantial set of GUI widgets classes for accessing SQL databases (ODBC, MySQL, PostgreSQL, Oracle, SQLite) QScintilla, Scintilla-based rich text editor widget data aware widgets that are automatically populated from a database an XML parser SVG support classes for embedding ActiveX controls on Windows (only in commercial version) To automatically generate these bindings, Phil Thompson developed the tool SIP, which is also used in other projects. History PyQt was first released by Riverbank Computing in 1998. In August 2009, Nokia sought for the Python binding to be available under the LGPL license. At the time, Nokia owned Qt Software, the developer of QT. After failing to reach an agreement with Riverbank Computing, Nokia released their own binding, PySide, providing similar functionality. Main components PyQt4 contains the following Python modules. The QtCore module contains the core non-GUI classes, including the event loop and Qt's signal and slot mechanism. It also includes platform independent abstractions for Unicode, threads, mapped files, shared memory, regular expressions, and user and application settings. The QtGui module contains the majority of the GUI classes. These include a number of table, tree and list classes based on the model–view–controller design pattern. Also provided is a sophisticated 2D canvas widget capable of storing thousands of items including ordinary widgets. The QtNetwork module contains classes for writing UDP and TCP clients and servers. It includes classes that implement FTP and HTTP clients and support DNS lookups. Network events are integrated with the event loop making it very easy to develop networked applications. The QtOpenGL module contains classes that enable the use of OpenGL in rendering 3D graphics in PyQt applications. The QtSql module contains classes that integrate with open-source and proprietary SQL databases. It includes editable data models for database tables that can be used with GUI classes. It also includes an implementation of SQLite. The QtSvg module