The Quarrel tool renders UML diagrams from text-based, declarative inputs for quick and easy modeling, as described in the UML as Sketch practice.
UAS is the acronym for UML as Sketch. The original name for the project was going to be 'UML as Sketch', but I didn't like taking the name of an idea or principle and using it in a program that implement that idea.
It would be like creating a window-based operating system and calling it... well, you get the idea.
The UAS was included in the name of the project just to reaffirm exactly what the program does.
The Unified Modeling Language, created by the Object Modeling Group, is a graphical syntax for specifying and documenting the elements of software systems. It has a robust and powerful vocabulary that can represent the most complex parts of a software system. But it is also good as representing simple systems or small parts of complex systems.
The vast majority of UML tools try to implement as many of the features in the UML specification as possbile. This depth is needed when you want to design or document a complex system. However, we often find that we want to quickly and concisely document a small system or sub system using UML notation, possibly in an informal setting. These large, powerful tools don't satisfy this use case very well.
These quick, informal diagrams are typically drawn by hand on paper or white board. Because they are informal, they may be hastily drawn using sloppy text or incorrect UML notation. Both of these reduce the value of the diagrams as a communication tool. Also, it is very difficult to clearly revise these diagrams w/o redrawing entire thing. Finally, because they are captured on paper or whiteboards, the diagrams are not easily persisted in a digital form.
This problem is discussed by Martin Fowler in the following web pages:
Folwer concludes the UmlAsSketch entry with "comphrehensiveness is the enemy of comprehensibility". This really does summary the problem well. The UML spec, the tools and the ideal diagram are all made so complex by the need to cover every possible need, that one can't just start using them with out first fully investing yourself in them. This is not always an option or productive.
Quarrel will address these problems by making it possible to quickly create clear and accurate diagrams that are consistent with the UML specification, without using a heavy weight software tool.
Once the 'UML as Sketch' name had been set aside, a replacement was needed. The ability to quickly create UML diagrams has been the key motivation behind the tool. So, I was looking for words starting with 'q' that I could reverse engineer into an acronym. Quarrel popped into my mind, for some strange reason. So, I looked it up on Wikipedia. It seemed like a good analogy.
There is a tag line in there some where... "UML that's fast and to the point"? Slightly cheesy, but then most classic tag lines do have an aroma of Limburger about them.