R is a free software programming language and software environment for statistical computing and graphics. The R language is widely used among statisticians and data miners for developing statistical software and data analysis.

RabbitMQ is open source message broker software (sometimes called message-oriented middleware) that implements the Advanced Message Queuing Protocol (AMQP). The RabbitMQ server is written in the Erlang programming language and is built on the Open Telecom Platform framework for clustering and failover. Client libraries to interface with the broker are available for all major programming languages.

RACF is an IBM security management product that provides access control and auditing functionality for its mainframe (large server) operating system, OS/390 (MVS) as well as for its VM operating system.

A computer dedicated to use as a server and designed to be installed in a framework called a rack. The rack contains multiple mounting slots called bays, each designed to hold a hardware unit secured in place with screws. 

Rackspace Certified Technician for OpenStack by Rackspace Hosting

An IT hosting company based in San Antonio, Texas, USA. They offer Security, Data Protection, Application, and Cloud services. Its clients include 40% of the members of the Fortune 100.

A type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies from 300 GHz to as low as 3 kHz. 

RadoGroup is a class used to create a multiple-exclusion scope for a set of radio buttons. Checking one radio button that belongs to a radio group unchecks any previously checked radio button within the same group.

Ruijie Authorized Instructor on RCNA (RAI-RCNA) by Ruijie Networks

Ruijie Authorized Instructor on RCNP (RAI-RCNP) by Ruijie Networks

An open source desktop customization tool thats allows you to customize skins for memory, battery power, RSS feeds etc.

A memory subsystem that promises to transfer up to 1.6 billion bytes per second. The subsystem consists of the RAM, the RAM controller, and the bus (path) connecting RAM to the microprocessor and devices in the computer that use it. 

RES Automation Manager 2011 Certified Professional (RAMCP 2011) by RES Software

RES Automation Manager 2011 Certified Professional, including Service Orchestration (RAMCP 2011-SO) by RES Software

RES Automation Manager 2014 Certified Professional (RAMCP 2014) by RES Software

The place in a computer where the operating system, application programs, and data in current use are kept so that they can be quickly reached by the computer's processor.