Jonathan Riddell

UML Modelling in Free Software with Umbrello

Bazaar style collaborative development of Free Software has a reputation for being haphazard and without care for careful planning of the design of the software. The Unified Modelling Language can be used to create diagrams of software giving an abstracted view impossible with pure programming code.

So far Free Software UML modelling programmes have been restricted to general diagramming programmes such as Dia and Kivio, which lack a proper understanding of the rules of UML and can not perform functions such as code import or export.

Umbrello UML Modeller, of which I am the project administrator and lead programmer, has recently become part of KDE and is due to be released with the next major version of KDE (3.2). An independent release of Umbrello is also available now.

UML can be used to create diagrams of programmes which are directly related to the resulting software code, specifying classes, their attributes and methods and the relationship between those classes. Using Umbrello's code generators, available for an increasing number of programming languages, these diagrams can be used as a replacement for the early stages of programming. Use case and component diagrams give a higher level of abstraction which allow a programmer to develop their ideas about the programme before having to think about codeing issues. UML diagrams can also be used for documentation of a programme, Umbrello is being used for this by Quanta HTML editor.

Because UML is standardised and language independant its simple diagrams can be understood by an increasing number of programmers, an incredible help when developing with coders on the other side of the world who you've never met. Unfortunatly Umbrello, like an increasing number of Free Software programmes, is threatened by software patents which if upheld could be used to restrict the functionality the programme can provide.