1. A computer-implemented method comprising: at a server computer, compiling a fact base and a set of business rules in accordance with a first platform definition model to derive a pre-compiled platform-specific fact base and a set of pre-compiled platform-specific business rules suitable for evaluation and execution by a client-side business rule engine configured to operate as an extension of a browser application consistent with the first platform definition model; and communicating to the browser application the client-side business rule engine, a subset of the pre-compiled platform-specific fact base and a subset of the pre-compiled platform-specific business rules so as to enable the client-side business rule engine to evaluate and execute the subset of pre-compiled platform-specific business rules at a client computer executing the browser application.