Acronym for Virtual Address Extension, the most successful minicomputer in history (possibly excepting its immediate predecessor, the PDP11). It was released in 1978 and was only retired recently, in 2000, in favour of the AlphaServer series now sold by HP.
The VAX was the Hacker's favourite machine until the advance of the microcomputer (the IBM PC) in about 1986. It is especially noted for its large, Assembler-programmer-friendly instruction set – an asset that became a liability after the RISC revolution. VAX is also a British brand of vacuum cleaner whose advertising slogan, "Nothing sucks like a VAX!" became a battle-cry of RISC partisans. It is even sometimes claimed that DEC entered a licencing deal that allowed them to market VAX computers in the UK in return for not challenging the vacuum cleaner trademark in the US.