The REST of Radovan Janecek's List

I've commented on one item from Radovan's list already. Now for the REST...

any other metadata has to be referenced from the representation of the resource

This is good. Semantic nets typically connect data (e.g. "frames" and "slots") and metadata (e.g. "facets" of a slot) directly. I would expect this to be so for a semantic web as well.

use of REST is not always appropriate (even if theoretically it can be used almost everywhere)

This is almost certainly so. But I suppose it is more broadly appropriate than its current range. And less clear is what is more appropriate in those other cases. Certainly there are cases where pre-existing systems are more appropriate. But what of the up-and-coming distributed systems technologies?

REST might be inappropriate especially if the integrated legacy system defines its own non-RESTful abstractions (e.g. SAP's BAPI).

Certainly there will be these cases. But I'm not sure SAP R3 can be put in that category. First, SAP has provided at least a couple of web-services-like interfaces to R3 and newer components. This is settling into the Netweaver/XI integration platform.

I don't know much about this yet, but I don't see why REST would be incompatible. One of the best presentations at OSCON 2003 was convincingly about a Perl and REST interface to R3.

use of REST is especially appropriate for generic system-level services that are expected to be used by robots (registry, security, management, reporting)

I think you are underestimating what a "robot" (i.e. an "interpreter" of semi-structured information) can do. See the Experiments with OVAL paper for a variety of examples using very modest software.

REST is appropriate for hypermedia, of course ;-)

Maybe a good discussion could be about what is suitable for representation as a hypermedia?

building REST applications, WS-* should be used wherever possible to ensure interoperability

Maybe this should be turned around a bit to say that WS-* should be defined to be compatible with the web.

RDF/OWL is more important for REST applications than it seems today

I think generally we need to learn how to build more evolvable application-specific semantic web interpreters. I know a little about RDF and less about OWL, although I am familiar with older semantic net languages. I think this statement could be so. But again referring to OVAL, a lot can be accomplished without getting to deep into heuristics.