wxWidgets is a cross-platform C++ GUI library, offering classes for all common GUI controls as well as a comprehensive set of helper classes for most common application tasks, ranging from networking to HTML display and image manipulation. wxWidgets uses native widgets on all platforms whenever possible and fills missing gaps on some platforms using generic controls written with wxWidgets itself.
FLTK (pronounced "fulltick") is a cross-platform C++ GUI toolkit for UNIX/Linux (X11), Microsoft Windows, and Mac OS X. It provides modern GUI functionality without the bloat, and supports 3D graphics via OpenGL and its built-in GLUT emulation. FLTK is designed to be small and modular enough to be statically linked, and also works fine as a shared library. It also includes an excellent UI builder called FLUID that can be used to create applications in minutes.
Xpdf is a viewer for Portable Document Format (PDF) files. (These are also sometimes also called 'Acrobat' files, from the name of Adobe's PDF software.) The Xpdf project also includes a PDF text extractor, PDF-to-PostScript converter, and various other utilities. It runs under the X Window System on UNIX, VMS, and OS/2. The non-X components (pdftops, pdftotext, etc.) also run on Win32 systems, and should run on pretty much any system with a decent C++ compiler. Xpdf is designed to be small and efficient. It can use Type 1 and TrueType fonts.
Roxen WebServer is a complete Web server. It is platform-independent, modular, and features a version with strong 128/168-bit encryption. Add-on products for information retrieval, visitor behavior analysis, and powerful tools for application development offering connectivity to databases are available. Altogether the Roxen Platform is a secure Web-based workgroup solution for time and cost-efficient content and Web site management.
Berkeley DB (libdb) is a programmatic toolkit that provides embedded database support for both traditional and client/server applications. It includes b+tree, queue, extended linear hashing, fixed, and variable-length record access methods, transactions, locking, logging, shared memory caching, database recovery, and replication for highly available systems. DB supports C, C++, C#, Java, PHP, and Perl APIs. It supports key-value pair (NoSQL), SQL, and Java Object formatted data. It is available for a wide variety of Unix platforms as well as QNX, Android, Mac OS X, and several varieties of Windows.
Zsh is a UNIX command interpreter (shell) which of the standard shells most resembles the Korn shell (ksh). It includes enhancements of many types, notably in the command-line editor, options for customising its behaviour, filename globbing, features to make C-shell (csh) users feel more at home and extra features drawn from tcsh.
SmartEiffel is the GNU Eiffel Compiler. It is intended to be a complete, though small and very fast, Eiffel compiler. The current distribution includes an Eiffel to C compiler, documentation tools, a pretty printer, and various other tools including an Eiffel debugger. It also includes a large library of classes distributed under the terms of the MIT/X Consortium License. Eiffel is an advanced object-oriented programming language that emphasizes the design and construction of high-quality and reusable software.