A C++ based library, that can be used to make programs using functions as in VB. The library has 25 classes ranging from GUI, Threads, String, Active-X. Simple way to convert VB code to C++. [Open source, Qt Public License (QPL)]

A set of C++ libraries to speed development and extend application capability. [Open source, GPL]

A cross-platform C++ library providing high-performance and portable classes for multi-threading, I/O, networking, Unicode and XML parsing. [Commercial]

C++ bindings for ORBit.

A high performance C++ application framework which provides many classes needed for real-world application development, emphasing on ease of use, size and stability. [Open Source, LGPL]

Documentation and Online-Presentations about STL and generic programming.

A cross platform C++ framework with support for sockets, files, streams, encoding, compression, encryption, threading, times/dates, networking, URLs, http, XML, XPath, collections, generics and databases.

A non-intrusive enhancement of C++ to add runtime reflection capabilities. [Open source, LGPL]

C++ class library which provides a partially-compatible replacement for the well-known string class, which is capable in the most popular operations on strings such as breaking down to words/tokens, conversion to numbers. [Open source, LGPL]

a free C++ class library for Microsoft Windows. All source files of the library and a lot of sample programs are available.