Review on yUML by Dennis Reed

The simplicity of use is great, you can drag-drop elements from palette directly into your diagram (or import them via *.udl file).

In addition I highly recommend creating own templates or libraries where we could save many common UDLs for our customers that they will be able to load in their next projects straight away - no need to download tons of files each time! I don't like some colors used by default but it's easy enough to change those as well if needed; however feel free not limited only with my suggestions :) Try this tool out at least once before buying license because its price isn't cheap even compared to other similar products available today. We are solving problems related user experience during software development process such as how documentation should look & behave like when users first enter product page/documentation section after installation.