This is not only a fascinating website in general, but in one spot has a quite novel - not perfect, but nicely innovative - interaction model for a tree of information.  Does a decent job of both showing the overview of information available and offering more information at various levels, in context, in response to interaction.
<br><a href="http://www.schematic.com/#/HowWeDoIt/ProjectProcess/">http://www.schematic.com/#/HowWeDoIt/ProjectProcess/</a><br><br>-R. <br><br><br>