Portable Network Graphics (PNG) Specification (Third Edition) is now a W3C Recommendation

The PNG Working Group published Portable Network Graphics (PNG) Specification (Third Edition) as a W3C Recommendation. This document describes PNG (Portable Network Graphics), an extensible file format for the lossless, portable, well-compressed storage of static and animated raster images. PNG provides a patent-free replacement for GIF and can also replace many common uses of TIFF. Indexed-color, greyscale, and truecolor images are supported, plus an optional alpha channel. Sample depths range from 1 to 16 bits.

The Third Edition adds Animated PNG and High Dynamic Range (HDR) PNG.