The WebFonts Working Group has published a W3C Recommendation of WOFF File Format 1.0. This document specifies the WOFF font packaging format. This format was designed to provide lightweight, easy-to-implement compression of font data, suitable for use with CSS @font-face rules. Any properly licensed TrueType/OpenType/Open Font Format file can be packaged in WOFF format for Web use. User agents decode the WOFF file to restore the font data such that it will display identically to the input font. Learn more about the Fonts Activity.