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 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.
Eric is a full featured Python and Ruby editor and IDE, written in Python. It is based on the cross platform Qt GUI toolkit, integrating the highly flexible Scintilla editor control. It is designed to be usable as an everyday quick and dirty editor as well as being usable as a professional project management tool, integrating many advanced features that Python offers the professional coder. Eric includes a plug-in system, which allows easy extension of the IDE functionality with plug-ins downloadable from the net. Current stable versions are Eric4 based on Qt4 and Python 2 and Eric5 based on Python 3 and Qt4.
The OpenSSL Project is a collaborative effort to develop a robust, commercial-grade, fully featured, and Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) as well as a full-strength general-purpose cryptography library.
NoMachine NX is a fast terminal server and desktop virtualization system based on the X11 protocol. NX is an order of magnitude faster than VNC or X11 and can run on bandwidth as narrow as 10 kBit/sec. In addition, NX translates and embeds the MS Windows Terminal Server and VNC protocols into X/NX, enabling users to compress and accelerate remote Windows and VNC sessions. The NX project provides a suite of libraries and X11 proxying agents implementing efficient compression and optimized transport of X11, SMB, IPP, HTTP, and arbitrary protocols like audio and video over the Internet.
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.
Doxygen is a cross-platform, JavaDoc-like documentation system for C++, C, Objective-C, C#, Java, IDL, Python, PHP, VHDL, and Fortran. Doxygen can be used to generate an on-line class browser (in HTML) and/or an off-line reference manual (in LaTeX or RTF) from a set of source files. Doxygen can also be configured to extract the code-structure from undocumented source files. This includes dependency graphs, class diagrams and hyperlinked source code. This type of information can be very useful to quickly find your way in large source distributions.