Abstract: A system for executing software, wherein a computing device stores first software instructions for a code execution module such that, when the first software instructions are executed, the computing device will: receive, for execution by the code execution module, second software instructions; create one or more immutable software nodes described in the second software instructions; determine that the second software instructions comprise an instruction to begin a simulated change at runtime of the one or more immutable software nodes; store the simulated change in a simulated change apparatus; using the simulated change apparatus, perform one or more operations of the second software instructions as if the one or more immutable software nodes had been changed in memory, during a period of time where each of the one or more immutable software nodes is guaranteed to retain logical immutability; and output results of the one or more operations.

Abstract: A system for executing software, wherein a computing device stores first software instructions for a code execution module such that, when the first software instructions are executed, the computing device will: receive, for execution by the code execution module, second software instructions; create one or more immutable software nodes described in the second software instructions; determine that the second software instructions comprise an instruction to begin a simulated change at runtime of the one or more immutable software nodes; store the simulated change in a simulated change apparatus; using the simulated change apparatus, perform one or more operations of the second software instructions as if the one or more immutable software nodes had been changed in memory, during a period of time where each of the one or more immutable software nodes is guaranteed to retain logical immutability; and output results of the one or more operations.

Abstract: A network management system has a network monitor arranged to monitor the load on elements of a computer network and to reconfigure the network when necessary to optimize its performance. The network configuration is carried out by servers in the network in response to an appropriate instruction from the network monitor. The servers operate to divert traffic from overloaded elements in the network by modifying both source and destination addresses of the transmitted data packets. In this manner the processing or database loads can be spread optimally among a plurality of servers in the network.