• Theoretical grounding. An annotation itself is simply a way to provide metadata (for example, consider poshformats or microformats) or to link an object with a conceptual description. Carlos Pedrini and his colleagues describe various ways additional layers have been built, including OWL-S and WSMO's grounding to SAWSDL, which use richer, theoretically grounded descriptions. 3
• Adoption and use cases. A Google search for either "Sawsdl" or ".sawsdl" will give more than 15,000 documents and provide links to tools and enhancements (for example, for enhanced annotation or discovery of SAWSDL documents). Such a search will also give many use cases — including academic and commercial, simple and complex — in several domains such as life sciences (for example, caBIG project) and financial services (see www.securitiestechnologymonitor.com/issues/19_50/22047-1.html). SAWSDL isn't a solution for annotating all types of services or Web resources. Correspondingly, newer efforts, including two recent W3C submissions, SA-REST ( www.w3.org/submission/sa-rest) and WSMO-Lite ( www.w3.org/Submission/2010/SUBM-WSMO-Lite-20100823), either build on or provide complementary solutions to SAWSDL and related annotation work.
• Dynamic invocation. The basis of Shi's comment on this topic is unclear to me. A Google search on "dynamic service search, sawsdl" gives several examples, such as support for dynamic service binding, invocation, and other issues. 4