The ICL 2900 Series was a range of mainframe computer systems announced by the UK manufacturer ICL on 9 October 1974. The company had started development under the name New Range immediately on its formation in 1968. It was not designed to be compatible with any previous machines produced by the company, or with any competitors' machines; rather, it was conceived as a synthetic option combining the best ideas available from a variety of sources.
When ICL was formed in 1968 as a result of the merger of International Computers and Tabulators (ICT) with English Electric Leo Marconi, the company considered a number of options for its future product line. These included enhancements to either ICT's 1900 Series or the English Electric System 4, and a development based on J K Illiffe's Basic Language Machine. The option finally selected was the so called Synthetic Option: a new design starting with a clean sheet of paper.
As the name implies, the design was influenced from many sources. These included ICL's own earlier machines. The design of Burroughs mainframes was influential, though ICL rejected the concept of optimising the design for one high-level language. The MULTICS system provided other ideas, notably in the area of protection. However, the biggest single outside influence was probably the MU5 machine developed at Manchester University.