1. A computer-readable memory medium storing program instructions executable to: include a plurality of test executive steps in a test executive sequence in response to user input, wherein each test executive step includes control functionality implemented by a test executive engine; configure each of the test executive steps to call a user-supplied code module in response to user input; and execute the test executive sequence under control of the test executive engine, wherein said executing comprises the test executive engine executing each of the test executive steps in the test executive sequence; wherein for each respective test executive step in at least a subset of the test executive steps in the test executive sequence, said executing the respective test executive step comprises: the test executive engine executing the control functionality of the respective test executive step in a first process; and the test executive engine invoking the user-supplied code module called by the respective test executive step for execution in a different process other than the first process; wherein the at least a subset of the test executive steps includes a first test executive step, wherein the control functionality of the first test executive step comprises post-functionality to be performed after the user-supplied code module called by the first test executive step finishes execution, wherein the test executive engine executes the post-functionality in the first process after the user-supplied code module called by the first test executive step finishes execution.