Germany's Gentleware Challenging Market Leaders
Although Poseidon falls short of some of its more commercial rivals in one or two areas like code generation (the version I downloaded could generate Java and HTML but not C++), it has other features like cognitive support that make it unique among CASE tools. Gentleware is working aggressively to productize ArgoUML and adding a raft of features including undo, redo and drag 'n drop of model elements, forward and reverse engineering of code, support for all UML diagram types and integration with Sun's open-source Forte for Java NetBeans IDE. The latest version of Poseidon also sports a plug-in mechanism that allows third-party vendors to extend the basic toolset with features like code and documentation generators, and simulation and test modules.

Germany-based Gentleware charges €199 Euro or around $179 for the downloadable Standard Edition of Poseidon. An expanded Poseidon Developer Edition is in the works for sometime early next year. Developers still have the option of reviewing, customizing, and improving the basic ArgoUML source code via the open-source Web site http://argouml.tigris.org that Jason Robbins started.

Anecdotally, for you fans of Greek mythology, the name Argo comes from the boat that Jason of Jason and the Argonauts fame sailed on. Poseidon was the name of the sea god that protected and saved the Argo.

	Figure 2 | Go here for a closeup of CanyonBlue's Cittera.

A Web-Savvy UML Collaborator
CanyonBlue's Cittera is the first UML tool to support simultaneous real-time collaboration—meaning modelers in different geographic locations can work together at the same time on a UML model. Cittera's collaboration features like real-time chat and an integrated visual whiteboard allow you to create a virtual development workplace across geographic boundaries. This means that your whole software team—from business analysts to project leads to developers to testers—can potentially work together in unison throughout the entire development lifecycle. The tool also gives you a good way to create an audit trail of your design decisions by automatically storing messages and other historical data, such as model annotations. With advanced change tracking that uses different colors for model elements from various contributors (see Figure 2), you can figure out who did what during different stages of your development cycle.

The real-time messaging or Bulletin Board feature is an especially well thought-out part of Cittera. The extensive search capabilities in the Bulletin Board, integrated with the Activity Log that tracks users' activities, lets you monitor the conversations that went into any particular model element. Modelers also have the ability to compare different versions of their models (whether created on- or off-line) and integrate them at different points in time in accord with other online collaborators (Cittera is built on the concept of privileged users or 'model owners' who can accept or reject changes to their individual models).

Cittera supports XML, Java, C++ and is compliant with the UML 1.3 standard. Cittera costs $250 per developer license when hosted on your own servers. The product is also available on a subscription basis, hosted on CanyonBlue's servers and run as an ASP tool over the Internet.

Take Them For a Test Drive
With built-in decision support and collaboration features, both Poseidon and CanyonBlue are pushing the envelope of UML modeling tool design. Because these innovative features haven't made their way into more mainstream tools yet, you might be tempted to think that only a team that's made up of highly trained, motivated and experienced UML experts will be able to fully use either of these tools. But it's more likely that development teams with a wide range of UML skills—from novice to expert—will be able to profitably take advantage of capabilities like decision support and collaboration, since both features can effectively leverage the expertise of a small number of UML-proficient developers. Whatever the level of your team's UML expertise, both of these tools warrant a test drive.

By making it easier to use UML to design and produce documented artifacts for your development team to refer to throughout the application development lifecycle, both of these tools can reduce conceptual flaws and promote a better understanding of work scope. This should have obvious competitive advantages in areas like the over-hyped but definitely emerging field of Web services—where applications will be delivered as reusable, interoperable services over the Internet, and rapid modeling of "what-if" software scenarios will become even more important.

Roger Smith is former technical editor of Software Development magazine. He has been a software developer for more than 15 years. Introduction In this Article Introduction Germany's Gentleware Challenging Market Leaders