If you do not have the cash to spend into VERY expensive software like ADS from agilent, Microwave Office from AWR...., and you want to do some simple RF/MW simulation or Spice simulation, you can now have the opportunity to load the open source software QUCS (quite universal circuit simulator)
This software gives you the base of a circuit simulator, with examples, technical papers and help which can be downloaded from the QUCS site. It 's very easy to learn, and you also have the opportunity to see what is under the engine, giving researcher an tool where they could add up their contribution.
Another open source software for people wanting to build some PCB is KiCAD, this software may need little more time for the user to understand and use but it can do some very nice PCBs.
When using KiCAD you first need to build your schematic and then import it to your layout using netlist. You can also add some new element into the library, and use the 3D option to visualise your design.
Few bugs are there but they do not stop you from doing some nice board.
One of the bug is that you need to create a library for each new element that you want to add, but this would be probably be fixed by the time that you read this article.
Maybe one more thing is needed would be an good open source EM simulator, a bit more complex task to realised, but I believe that one day...