An increasingly common server deployment scenario involves dedicated servers supporting single applications. In such cases, system software need not be concerned with fairness between applications, but should instead focus on serving the precise needs of one particular application. To meet this goal, system software must permit applications to express their needs and must evolve to meet those needs.

The fixed abstractions in conventional systems software militate against both expression of applications? needs and against restructuring of system components to meet those needs. The compliant systems architecture (CSA) is a novel language-based software architecture that promises to enhance the extent to which system software is compliant to the applications it supports. Using our CSA instantiation, we identify several tactics for evolving system software to enhance compliance. The principal contribution of this paper is practical validation of CSA, via case studies of these tactics, demonstrating improved system services for an application.