FreeType & Patents

The TrueType Bytecode Patents Have Expired!

Since May 2010, all patents related to bytecode hinting have expired worldwide. It it thus no longer necessary to disable the bytecode interpreter, and starting with FreeType version 2.4, it is enabled by default.

The affected patents were

Other Patent Issues

The colour filtering algorithm of Microsoft's ClearType technology for subpixel rendering is covered by patents; for this reasons the corresponding code in FreeType is disabled by default. Note that subpixel rendering per se is prior art; using a different colour filter thus easily circumvents Microsoft's patent claims.

Last update: 18-Dec-2012