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 are
Other patent issues
The colour filtering algorithm of Microsoft's ClearType technology
for subpixel rendering is covered by patents. Note that subpixel
rendering per se is prior art; using a different colour filter thus
circumvents Microsoft's patent claims.