The many faces of Indigo

Sometimes getting away from the keyboard can really help you get your thoughts in order. I just got back from NYC, where I spent a long weekend with my family. I left the laptop at home (my 9 month old seems to occupy all my vacation time ;-), but I still had time to think about Indigo and how it will fit into and change the Web services world.

Just before I left, I read David's Indigo intro piece on the MSDN Longhorn site. It lays out the basics and, among other things, talks about the different types of channels that an endpoint can use, including:

1. BasicProfileHttpBinding
2. BasicProfileHttpsBinding
3. WsHttpBinding
4. WsDualHttpBinding
5. NetTcpBinding
6. NetNamedPipeBinding
7. NetMsmqBinding

My first reaction to this list is that Indigo is making it really clear which of “My 3 Web Service Stacks” you are using when you pick a given channel. If you are using either 1 or 2, you can be reached by anyone who speaks SOAP and WSDL. When you use 3 you can be reached by anyone who speaks WS-* (or an overlapping subset of the specs that Indigo speaks). When you use 4 you can talk to anyone who understands that pattern (I'm pretty sure BEA has an equivalent feature). When you use 5, 6 or 7 you can reach anyone using Indigo (or any other tool that replicates the behavior of Indigo).

My second reaction is to wonder whether developers will see a distinction between using Indigo and using Web services. If you build an endpoint that uses an Indigo-only named pipe or TCP binding and supports multiple stateful service instances, you're doing something closer to DCOM or .NET Remoting than to Web services. What you're doing may be “service oriented” (whatever that actually means), but is it Web services? And if it's not, will the fact that Indigo is using the same APIs to do very different things with very different implications going to help or hurt people?

One thing is clear, there is going to be a cottage industry of people who offer advice on which features of Indigo you should use to achieve a given goal. I'll probably be one of them. ;-)