C++

C++ began as a pre-processor for C, and eventually evolved into a programming language in its own right, adding object-oriented classes to a basic syntax still derived from C. It has achieved a great deal of popularity, and has been standardized as ISO/IEC 14882.

The name refers to the "increment" operator ++ applied to C, and is not the grade the language's creator received for it as a student project!

C# and Objective-C are other descendants of C which take different approaches to adding object-oriented classes.

ISO standard
The final standards are only released for a purchase fee, however the working drafts are available for free.

The C++ Programming Language
Written by the language creator Bjarne Stroustrup, the book served as the original C++ reference before being standardized.

Compiler extensions
Compilers commonly include non-standard extensions that might be used.
 * Clang
 * GCC: C++, C
 * Visual C++

Links

 * Wikipedia article
 * The Grand C++ Error Explosion Competition
 * GCC-XML: convert C++ code to XML
 * A Modest Proposal: C++ Resyntaxed (archive.org copy)
 * Thinking in C++ 2nd Edition by Bruce Eckel (free online book)