I spent this morning with Dave Mitchell, the CTO of Canyon Bridge, a Utah-based start-up. From looking at their Web site, you'd guess that they sell a product that gives you Web-based access to Microsoft Exchange, but its actually what's under the covers that interested me.
Second, they built a SOAP front-end for Exchange so that they can deal with Exchange using SOAP calls rather than MAPI. Of course once that's done, you could substitute something else for Exchange itself and that's just what they've done. They've got a Linux/MySQL replacement for Exchange in Alpha right now.
Thirdly, they build a server side orchestration language for controlling the presentation and interacting with SOAP-based services so that the action of the client is controlled using an XML-based business logic language.
To demonstrate the power of this, one of the demonstrations they showed me was a Salesforce.com integration with their Outlook replacement. Not only could you see all of your Exchange-based calendar, contact, and messaging in the tool, you could also see all of your leads and appointments from Salesforce.com. The calendar showed Exchange hosed appointments in an integrated view with the Salesforce.com appointments. Very cool. What's more, they built it in 3 days.
So, while this company may be starting out selling a Web-based Outlook replacement, they're tools make them much more than that. When I saw what they were doing I thought "This is what I imagined Web services would be like."
Canyon Bridge is ultimately a Web services intermediary, but differs from all that I've seen in that its not trying to do management and its not about automating business processes. The tool is used to orchestrate Web services to create a user-facing application. In fact, you'd probably want to use the Canyon Bridge intermediary in concert with a more traditional intermediary to do security, routing, and so on.