MasterCook is a wonderful software program from SierraOnline in conjunction with Betty Crocker. It contains a number of recipes, divided into various "cookbooks" and categories, and it also allows you to input your own creations (or recipes from other sources) and do neat things with them, such as get a nutritional analysis (like I did for this one) or scale them up or down (which I have done with medieval recipes, when planning to serve 300+ people--with a recipe that might serve four or six).

I don't use it terribly often, but I suspect I'll become more proficient with it now that I'm committed to this WOL. It's far simpler for me to type in the ingredients and click on an icon to get an analysis, than to sit down with a calculator, pencil, and paper.

Sorry to say, I can't tell you how much it costs: I got my copy as a gift from a fellow medieval-re-creationist cook.