Systems and methods according to various embodiments disclose a worker process manager adapted to spawn one or more worker processes on a server and to load an application on each of the worker processes. The worker process manager is adapted to isolate the one or more worker processes from each other and to control resource usage by the worker processes. A resource manager is adapted to detect applications that overuse system resources. The worker process manager is adapted to isolate worker processes and to control resource usage using one or more of the following techniques: least-privilege execution, messaging isolation, credentials isolation, data isolation, network isolation, fair share resource usage, and managed runtime security. Heuristic algorithms are used to detect applications that frequently overuse system resources that are unchargeable and that cause system unresponsiveness.