I'm new to timber framing, so I came up with some software that will help me analyze and study a set of plans before I make any cuts. Other beginners might find it useful. It's free, it can be uninstalled easily, and it doesn't make any changes to your system registry. Take a look at my home page (look under consulting; timber framing is listed on the left).

Jim H

Someone pointed out that not all joinery possibilities are included in the software. You can easily add any joint component by creating an image (I used Sketchup and exported to a jpg) and adding an entry to the standard joints list referencing that image. You can also replace the images that I made with images of your own.