Getting Started

Welcome to my * UML blog.




* UML is a set of free (as in beer) UML metamodels and a supporting editor. * UML is a language for building models with the following characteristics:

• Essential application analysis/requirements are kept separate from the implementation mechanics. (I avoided the word "details" here because it is a myth that there are more details in implementation than there are in the application rules. The details just happen to be different).

• All models are fully executable. This means that if you build a * UML model you can say "run" and it will execute just like any program code. Even though the model contains nothing but UML level concepts like classes, attributes, states, and action semantics, the models run without the need for any inserted C, Java, C++, Python or any other alien program language code. Now the models might be running on top of a virtual machine built in one of those languages, but there is no code in the models themselves. This is important because we need to keep the models separate from the implementation.

• All models concepts are expressed in a maximally parallel form. In most programming languages instructions execute in sequence unless parallelism is made explicit with, say, threads or processes/tasks. In * UML it is just the opposite. Everything runs in parallel (on an imaginary massively parallel architecture) and sequence only occurs where explicitly specified. A key benefit of a language like this is that once you build a set of models for an Air Traffic Control Application, for example, you can compile the models to platforms with a variety of parallelism implementation. The same models could be compiled onto a single processor architecture or onto a distributed processor architecture. Same models, different code generation. After all, the application rules don't change - why should the models that formalize those rules change? Only the implementation goo should vary.

• The modeling language itself should be have as few symbols/rules as possible. The less the better. This is because we want the language mechanics to fade into the background with the rules of the application brought to the forefront. The goal of a * UML model is to express the application rules as clearly as possible, in as much detail as possible, without specifying an implementation.

* UML is inspired by these books if you want to know more:

Executable UML
ISBN: 0201748045
Model Driven Architecture with Executable UML
ISBN: 0521537711
MDA Explained
ISBN: 0201788918

The purpose of this blog is to post technical notes and developments as I construct the * UML editor and accompanying metamodels.

By the way, you can download the current release at SourceForge:

http://sourceforge.net/projects/starruml/

Finally, my company's web page is here:
http://modelint.com

That's all for now.

- Leon