a tool-kit for creating "web 2.5 generation", include several useful stuff to work with semantic web (otology editor, gui for sparql query, ontology components...) and design RIAs's gui visually (html + ajax based apps, flash based apps,...)
Hemingway is a wysiwyg (what you see is what you get) online text editor which produces various standard and accessible HTML or WIKI formatted text output on each supported browsers.