Lynx is a file transfer protocol for use with modems, and the name of the program that implements the protocol. Lynx is based on a sliding window protocol with two to sixteen packets per window (or "block"), and 64 bytes of data per packet. It also applies run length encoding (RLE) to the data on a per-block basis to compress suitable data. Lynx was developed by Matthew Thomas, who released it as shareware in 1989. The protocol was supported primarily by the Lynx program, and appears to have seen little or no support in bulletin board systems (BBSs) or online services.