Last week the OMG adopted the superstructure document for UML 2. In practice this means that UML 2 is agreed on. There are numerous changes to the UML in UML 2 - it represents the biggest overhaul to the UML since the UML was originally agreed on. For general users the most obvious changes are probably:

• Interaction Frame notation added to sequence diagrams
• Collaboration diagrams renamed to communication diagrams
• Activity diagrams are no longer a special case of state diagrams - as a result they get a host of new things
• A notation for composite structures allows you to describe classes hierarchically

I've been monitoring the various incarnations of the UML closely for the last year or so, with the help of several kind souls on the various UML committees. As I've done this I've been revising (and occasionally re-revising) UML Distilled to bring it up to date with the new standard. Over the last couple of weeks various people on the UML committees have been reviewing the text and today I've released it to production. Addison-Wesley hope to get the new edition out onto the shelves sometime in August/September.