This is a node.js module, writen in C++, that uses libpng to produce a PNG image (in memory) from RGB or RGBA buffers. The module exports three objects: Png, FixedPngStack and DynamicPngStack. The Png object is for creating PNG images from an RGB, RGBA, or Grayscale buffer. The FixedPngStack is for joining a number of PNGs together (stacking them together) on a transparent blackground. The Dynamic