Big companies, like Amazon and AOL, offering 'Software as a Service' seem to focus on REST more than on SOAP. Having a Microsoft background myself I found this strange... ASP.NET webservices work great, so therefor why not use SOAP?
The number one great thing about REST is the ability to easily test a service by... typing the URL in you browser. This will at least allow you to test the GET operation on your REST service.
Microsoft's number one dude on SOAP, Don Box seems to be moving away from SOAP himself (or is he running?). Below is an abstract of Don's words during Microsoft Tech Summit 07 taken from Ben Galbraith's blog. Read the full item here.
Q: What is the future of REST?
Don: Interesting word that means different things to different people, such as:
1. Get the WSDL and XSD out of my face
2. Get the SOAP out of my face
3. Put the URI in my face
4. Respect GET
5. Embrace PUT and DELETE
“It turns out a lot of the headache people have with Web Services or WS-* is tied to XSD. XSD is more flawed than most technologies that roam the earth. I was on the committee that created it, and that was back when I made my money explaining complicated technologies to people for money, and man, I could hear the cash registers ringing in my ears.”
“Now my job is making things simple, which is unfortunate since I’m stuck with XSD.”
“XSD was a standard-committee driven piece of ####ing crap.”
“If you’re Sun, if you’re Microsoft, if you’re IBM, you can just throw a bunch of engineers in a room and make it all work. Sun is committed to making their stuff interop with WCF with Project Tango. But if you’re Matz, or DHH, or Larry Wall, you’re screwed, because you don’t have time to build out this stack and then make it interoperate.”