yydecode started life as a decoder for yEnc encoded binaries, which have recently appeared on Usenet. yydecode works almost identically to the infamous uudecode program. Version 0.2.8 and onwards contains a superset of uudecode's functionality, (ie. decodes standard uuencoded files, as well as Base64 [RFC2045] encoded files produced by uuencode) and hence can be used as a drop-in replacement in all circumstances.