Techniques and technologies are provided for testing network applications without communicating over a network layer communication link. For example, in one implementation, a system for testing network applications within a process is provided which includes at least one client user instance (CUI) module configured to execute in the process, a performance testing engine module (PTEM) configured to execute in the process, and a network application module configured to execute in the process. The CUI module has state information associated therewith. The PTEM includes a Request Driver Module (RDM) which generates information requests based on the state information received from the CUI. The network application module generates responses to the information requests.