RapidJSON
A fast JSON parser/generator for C++ with both SAX/DOM style API
...It was inspired by RapidXml. RapidJSON is small but complete. It supports both SAX and DOM style API. The SAX parser is only a half thousand lines of code. RapidJSON is fast. Its performance can be comparable to strlen(). It also optionally supports SSE2/SSE4.2 for acceleration. RapidJSON is self-contained and header-only. It does not depend on external libraries such as BOOST. It even does not depend on STL. RapidJSON is memory-friendly. Each JSON value occupies exactly 16 bytes for most 32/64-bit machines (excluding text string). ...