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.
The SeaMonkey project is a community effort to develop an all-in-one Internet application suite. It contains an Internet browser, email and newsgroup client with an included Web feed reader, HTML editor, IRC chat, and Web development tools, and is sure to appeal to advanced users, Web developers, and corporate users. It uses much of the Mozilla source code powering such successful siblings as Firefox, Thunderbird, Camino, Sunbird, and Miro.
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.
The Oracle (formerly Sun) Java Platform, Standard Edition (Java SE or JSE) allows you to develop and deploy Java applications on desktops and servers as well embedded and real-time environments. The Java Development Kit (JDK) contains the essential compiler, tools, runtime libraries, and APIs for developers writing, deploying, and running applets and applications in the Java programming language. The Java Runtime Environment (JRE) contains the runtime libraries and tools for running applets and applications.
GnuTLS is a secure communications library implementing the SSL, TLS, and DTLS protocols and technologies around them. It provides a simple C language application programming interface (API) to access the secure communications protocols, as well as APIs to parse and write X.509, PKCS #12, OpenPGP, and other required structures. It is intended to be portable and efficient with a focus on security and interoperability.