Sanjiva gave a talk at Google on Web services, which also touched on REST. Unfortunately there’s a lot of misinformation in there about REST, including a statement to the effect of “If you want to sign your message, you can’t use REST” (I don’t think I’m taking that out of context), plus a slide (@ 25:00) that includes the following;
REST vs. WS-* is the wrong battle - WS-* is used to create Service Oriented Architecture - REST is used to create Resource Oriented Architecture
When taken together with some other comments, it appears as though Sanjiva sees REST as an alias for HTTP (or perhaps HTTP/URI), which it isn’t of course. He’s certainly entitled to his own beliefs, but I think he would do well to spend a couple of days with his nose buried deep in Roy’s dissertation… and not just chapter 5. Until that happens, I’d personally avoid trying to make conclusions about how these different approaches may or may not relate, or may or may not compete.