JTLT is a general text based templating system that is very easy to use and powerful. It can be used for almost anything, including code generation for translators/compilers and HTML output for Java servlets. It features replaceable keys, nested block structures, an extensible macro system (even keys are implemented as macros), a separation of parsing and output generation, a separation of macro settings and parsing, in-memory caching of parsed templates, weak typing, and extensive documentation.
Libfbm is a C++ library for fast and accurate bulk-simulation of multi-dimensional (1D, 2D, 3D, .., 8D) Gaussian stationary processes, fractional Brownian motion, and fields with power-law power spectrum. It makes use of the circulant matrix embedding and FFT. Random number generation is provided by SFMT (SIMD-optimized Mersenne Twister) with a ziggurat based algorithm for normal distribution. For FFT functions, it depends on the FFTW library.