The present invention discloses a modified computer architecture which (50, 71, 72) enables an applications program (50) to be run simultaneously on a plurality of computers (M1, ... Mn). Shared memory at each computer is updated with amendments and/or overwrites so that all memory read requests are satisfied locally. During initial program loading (75), or similar, instructions which result in memory being re-written or manipulated are identified (92). Additional instructions are inserted (103) to cause the equivalent memory locations at all computers to be updated. In particular, the initialisation of JAVA language classes and objects is disclosed (162, 163) so all memory locations for all computers are initialized in the same manner.