Rserve is a versatile, scalable server enabling the efficient use of R from other applications through variety of protocols including QAP, WebSockets, HTTP and HTTPS. It acts as a server (TCP/IP or local sockets) which allows binary requests to be sent to R. Every connection has a separate workspace and working directory. Client-side implementations are available for many popular languages allowing applications to use facilities of R without the need of linking to the R binary. Rserve supports remote connections, user authentication and file transfer. A simple R client is included in this package as well. It also supports OCAP mode for secure remote procedure calls, including support for full event loop, asynchronous results/graphics and console I/O.