ScrapBook is a Firefox extension, which helps you to save Web pages and easily manage collections. Key features are lightness, speed, accuracy and multi-language support. Major features are:

* Save Web page
* Save snippet of Web page
* Save linked Web page
* Organize the collection in the same way as Bookmarks tree
* Full text search and quick filtering search of the collection
* Simple Editing of the collected Web page
* Text/HTML edit feature resembling Opera’s Notes

and its got RDF