The first modeling tool from Microsoft's new "Whitehorse" initiative expresses deployment topologies and the constraints that work upon them (e.g., by dropping a "Hardened IIS" component in your DMZ and a "Web Services" component in your middle-tier and connecting them, you are expressing a whole slew of constraints about what ports are open to whom, what sorts of connections will be accepted, etc.). This is not just a nicely pragmatic tool, it is also not something addressed by UML. I asked Keith Short if the decision to avoid (or at least delay) a direct conflict with UML was deliberate. "Absolutely," he told me.