Qt is a comprehensive, object-oriented development framework that enables development of high-performance, cross-platform rich-client and server-side applications. When you implement a program with Qt, you can run it on the X Window System (Unix/X11), Apple Mac OS X, and Microsoft Windows NT/9x/2000/XP by simply compiling the source code for the platform you want. Qt is the basis for the KDE desktop environment, and is also used in numerous commercial applications such as Google Earth, Skype for Linux, and Adobe Photoshop Elements.
GTK, which stands for the Gimp ToolKit, is a library for creating graphical user interfaces. It is designed to be small and efficient, but still flexible enough to allow the programmer freedom in the interfaces created. GTK provides some unique features over standard widget libraries.
WebGUI is a content management framework built to allow average business users to build and maintain complex Web sites. It is modular, pluggable, and platform independent. It was designed to allow the people who create the content to manage it online, rather than content management taking up the time of busy IT staff. WebGUI comes with a full host of features including shopping cart, subscriptions, forums, photo galleries, FAQs, link lists, blogs, SQL reports, a Web services interface, and a very configurable user privilege and profiling system.
Wt is a C++ library for developing Web applications with an API that is widget-centric and inspired by existing C++ graphical user interface APIs. To the developer, it offers abstraction of Web-specific implementation details, increasing the accessibility and portability. Under the hood, the library uses the latest techniques (HTML5, Ajax, WebSockets) to handle user events and update the Web page.
FOX is a C++-based toolkit for GUI development. It includes a rich set of widgets and has powerful yet simple layout managers, MDI widgets, and mega-widgets. FOX incorporates support for XDND for drag and drop, X clipboard and X Selection, watching other I/O channels and sockets, timers and idle processing, object serialization and deserialization, a registry to save persistent settings, and 3D widgets using Mesa or OpenGL. FOX works on Linux, IRIX, Solaris, HP/UX, AIX, Tru64 Unix, Windows 9x,NT,2K (VC++, GNUWIN32, Borland, VisualAge C++), FreeBSD, and Sequent.
U++ is a C++ cross-platform rapid application development suite focused on programmers' productivity without sacrificing runtime performance. Based on strictly deterministic design, it provides a viable alternative to garbage-collected platforms, even for business logic oriented problems.
gtkmm (previously known as Gtk--) is a C++ interface for the popular GUI library GTK+. It provides a convenient interface for C++ programmers to create graphical user interfaces with GTK+'s framework. Highlights include typesafe callbacks, widgets which are extensible by inheritance, and many classes that can be easily combined to quickly create complex user interfaces.
The Ecere SDK is a cross-platform toolkit for building software applications. It currently runs on Windows, Linux, Mac OS X (through X11), FreeBSD, and the Android OS. It should run on other Unix platforms with minor testing/tweaking. With the Ecere SDK, you can develop applications once and deploy them on all supported platforms alongside a lightweight runtime environment. It introduces eC, an object oriented language derived from and fully compatible with C, compromising neither runtime performance nor ease of use. A built-in 3D engine supporting both Direct3D and OpenGL is fully integrated.
WidgetServer is a Java/XML server-side GUI-framework which enables an application to run as either a monolithic Swing app, a client/server Swing app, or as a Web app without any change and without loss of functionality. An Eclipse Plugin is available as well. A rich widget set is supported that includes tree views, tabbed panes, split panels, and much more. Animations, all types of events, and several effects are supported, as well. A unified widget-based, object-oriented programming interface for Web and Swing GUIs is offered to the developer to control and assemble the GUI. Web applications are fully AJAX enabled. For Swing client/server applications, the framework handles client/server communication, including compression and security layers.