OpenRQ is a Java library that implements the RaptorQ FEC scheme described in RFC 6330. The aim is to provide to developers a library that is easy to use and incorporate in their applications, whilst maintaining RaptorQ’s acclaimed performance and resilience. Forward Error Correction (FEC) is a technique for the recovery of errors in data disseminated over unreliable or noisy communication channels. The central idea is that the sender encodes the message in a redundant way by applying an error-correcting code, which allows the receiver to repair the errors. RaptorQ is a fountain code, which are a class of erasure codes with two attractive properties: an arbitrary number of encoding symbols can be produced on the fly, simplifying the adaptation to varying loss rates; and the data can be reconstructed with high probability from any subset of the encoding symbols (of size equal to or slightly larger than the number of source symbols).