Boost was begun by members of the C++ standards committee Library Working Group to provide free peer-reviewed portable libraries to the C++ community. An additional objective is to establish "existing practice" and provide reference implementations so that the Boost libraries are suitable for eventual standardization. Indeed, the explicit intent is to propose many of these libraries for inclusion in the C++ Standard Library. The Boost Graph Library, formerly known as the Generic Graph Component Library (GGCL), is a collection of graph algorithms and data structures created in the generic programming style of the Standard Template Library (STL).
libkdtree++ is a C++ template container implementation of k-dimensional space sorting, using a kd-tree. It sports a theoretically unlimited number of dimensions, and can store any data structure. Provided the data structure, it provides operator[0 - k-1] to access the individual dimensional components (arrays, std::vector already do) and a std::less implementation for the type of dimensional components. It has support for custom allocators, implements iterators, and provides standard find as well as range queries. It has amortised O(lg n) time (O(n lg n) worst case) on most operations (insert/erase/find optimised) and worst-case O(n) space, and also provides a means to rebalance and thus optimise the tree.
libfactory++ is a C++ template framework for run-time dynamic type instantiation. You can register single classes or whole hierarchies, and then tell libfactory++ to instantiate objects using the registration key. libfactory++ differs from other factory approaches mainly in its flexibility. First, it can use any constructor a type supports, and allows you to choose (and configure) the constructor to use for each call to create(). Second, it supports custom allocators, allowing you to use, e.g., a memory pool rather than continuous invocations of 'new'.