How do I start doing service virtualization, stubbing or mocking today? A good overview of stubs and mocks can be found in the the GooS book. If you are a software developer try using Mockito to learn how to do do mocking. If you are a software tester try doing stubbing using TrafficParrot or SoapUI MockService. It's also worth reviewing any of the enterprise vendors like CA, IBM or Parasoft but as ThoughtWorks observed in Jan 2014 most of the innovation comes from practitioners contributing to open source.