The Art of C++

The Art of C++, or taocpp for short, is a collection of high-quality C++ libraries, written in a "modern" C++ style, with minimal external dependencies, straightforward interfaces, extensively tested and highly portable, and, last but not least, well documented.
Simplicity is an important design goal, in particular to provide no-surprise interfaces.
Continuous integration runs all the many tests with multiple compilers on multiple operating systems.
The Art of C++ was featured in Episode 162 of CppCast.