This monograph describes the theory behind Raptor codes, and elucidates elements of the processes behind the design of two of the most prominent members of this class of codes: Raptor (IETF RFC 5053) and RaptorQ (IETF RFC 6330).
This IETF document describes a fully-specified Forward Error Correction (FEC) scheme for the RaptorQ FEC code and its application to reliable delivery of data objects. Qualcomm Inc. made a statement about Intellectual Property Rights (IPR) related to IETF RFC 6330. More information on that can be found here.
This article discusses the design and analysis of Raptor codes , which have linear time encoding and decoding, and close to optimal recovery properties. RaptorQ can be thought of as a an exemplary member of the more general class of Raptor codes.