About: http://webisa.webdatacommons.org/57903580

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	it is nice that there is a preference tab to manage the extensions including updating and removing them.I tried it out and it works well.Update: One thing with Reader does not work as well as in Readability.
http://www.w3.org/ns/prov#wasQuotedFrom	blogspot.com