E-Prime is an industry standard experiment generator from PST. It takes a "drag-and-drop" approach to experiment creation but also allows for you to get your hands dirty by creating some custom code to get it to do exactly what you want. The interdace is very similar to Microsoft's Visual Basic 6.0 so programmers of that language should feel right at home. Everyone else - dont' panic! E-Prime is easy to get to grips with.
E-Prime version 1 does not let you open two experiments at the same time causing problems if you want to copy objects between experiments. This video demonstrates a trick to get two copies of E-Prime running concurrently to allow you do this this. This technique is not supported and I've found that exiting from E-Prime inevitably results in a crash (not before you've saved your experiment though). E-Prime version 2 does not require this trick as it will open multiple experiments.
Download Video (2.4MB) | Duration 1:28