The document discusses the differences between the traditional Web and the Semantic Web. The traditional Web links documents together through hyperlinks, while the Semantic Web links data using URIs and RDF. On the Semantic Web, resources are described through multiple representations including graphs of RDF data. Scripting can be used to build applications that retrieve and process Semantic Web data from multiple sources using the HTTP protocol and convert it to and from RDF. This merges the traditional Web and Semantic Web into a single Web.

1. Two
Webs!
Danny Ayers, 2007
Scripting for the Semantic Web Workshop
(“So where are the agents?”)

2. Web 2.0?

3. REST
OWL
URIs
HTTP
XML
RDF
WebArch
HTML
Links
Data

6. The Web

7. href
<a href=”documentB.html”>Another Doc</a>
documentA.html
documentB.html

8. representation
href
http://example.org/resourceA
http://example.org/resourceB
representation
href

9. Source : http://opte.org

10. The Semantic Web

11. http://example.org/resourceA
http://www.w3.org/2000/01/rdf-schema#seeAlso
http://example.org/resourceB

12. <http://example.org/resourceA>
<http://www.w3.org/2000/01/rdf-schema#seeAlso>
<http://example.org/resourceB>
.

13. resourceA resourceB
representation representation
href
:resourceA
rdfs:seeAlso
:resourceB
:resourceA :resourceB
representation representation
rdfs

14. resourceA resourceB
representation representation
href
:resourceA :resourceB
representation
rdfs:seeAlso
:resourceA
rdfs:seeAlso
:resourceB

15. The Web
The Semantic Web

17. href
http://example.org/resourceA
representation

18. Resource
A Resource has a set of Representations
of different (media) types [WebArch]
Rp Rp Rp
representation
representation
representation
mT mT mT
mediaType
mediaType mediaType
mT1 = text/html
mT2 = image/jpeg
mT3 = application/rdf+xml

19. Ideal
Resource
Rp Rp Rp
representation representation
representation
Individual representations of a resource
aren't necessarily “complete”

20. R
Representations may change over time
Rp0 Rp1 Rp2
representation
at time t0
representation
at time t1
representation
at time t2
text/html text/html text/html
mediaType
mediaType mediaType

21. <http://example.org/resourceA>
<http://www.w3.org/2000/01/rdf-schema#seeAlso>
<http://example.org/resourceB>
.

22. R
One or more of the Representations may
describe a Graph [RDF]
Rp
representation
application/rdf+xml
mediaType
describes

23. R
Rp
representation
application/rdf+xml
mediaType
describes

25. Server
Client
View
ServerServer

26. Data Processes
Server
Client
View

27. Web 2.0?

28. Data Processes
Server
Client
DataProcesses
View
Server
Server

30. Tyranny
of the
Browser

31. The Web
The Semantic Web

32. <a href=”documentB.html”>Another Doc</a>
documentA.html
documentB.html
html:href a rdf:Property .
documentA.html html:href documentB.html .

33. Model
Resources
Representations
HTTP Processes

34. “So where are the agents?”
- Jim Hendler

35. 9th
Life

36. Things that look like they work
in virtual worlds
* Commerce
(supports micropayments)
* Intellectual Property
(everyone owns what they build)
* Open Source
(between participants)

39. Source: http://home1.gte.net/pfingar/doc_mag2_f4.gif via Google Images

40. BehaviourRDF
Model
HTTP
Client
HTTP
Server
Comms
Bus
(The Web)

41. HTTP
Client
Comms
Bus
(The Web)
View

42. GET /index.html HTTP/1.1
Host: elsewhere.org
Link: <http://mysite.org/foaf.rdf>; rel="foaf"

43. <http://mysite.org/foaf.rdf#me> a :Person ;
:holdsAccount [
a :OnlineAccount ;
:accountServiceHomepage <http://openid.net> ;
openid:server <http://www.myopenid.com/server> ;
openid.delegate <http://me.myopenid.com/">
] .

44. BehaviourRDF
Model
HTTP
Client
HTTP
Server
Comms
Bus
(The Web)
View

45. BehaviourRDF
Model
HTTP
Client
HTTP
Server
Comms
Bus
(The Web)
View

46. What does
any of this
have to do with
Scripting?!

47. BehaviourRDF
Model
HTTP
Client
HTTP
Server
Comms
Bus
(The Web)

48. RDF
Model
HTTP
Client
HTTP
Server
handle(request) {
data = model.query(request)
if(data != null){
return format(data)
}else {
other_source
= model.lookup(request)
data =
get(other_source, request)
}
return format(data)

49. Possible Issues
* need for async behaviour within
request/response cycle
* system-level concurrency is unreliable?
* does messaging over HTTP even make sense?

50. * need for async behaviour within
request/response cycle
- threads, message queues!
tools are available, e.g. Quartz
* system-level concurrency is unreliable?
- the system is the Web
live with unreliability!

51. Does messaging over HTTP make sense?
does RPC/SOAP?
- occasionally (when you
control both ends of the wire)
does RSS/Atom syndication?
- server push can be simulated
through polling
Reliable messaging can be done, e.g. HTTPLR

52. Semantic Web
Web
Docs
SQL
DBs
XML
Formats
Other
Protocols
= ConverterToRdf

53. BehaviourRDF
Model
HTTP
Client
HTTP
Server
Comms
Bus
(The Web)
Other Data

54. Semantic Web
Web
Docs
SQL
DBs
XML
Formats
Other
Protocols
= ConverterFromRdf

56. Model
Resources
Representations
HTTP Processes

58. One
Web!

59. http://talis.com
Semantic Web
Application Platform

60. Thank you!
These slides online :
http://dannyayers.com/sfsw2007/slides