Web Directory by Internet-Web-Directory.com

Directory of public relations firms, think tanks, industry-funded organizations, and industry-friendly experts that work to influence public opinion and public policy on behalf of corporations, governments and special interests.

An extensively hyperlinked collection of facts, ideas, notes and humor to which anyone can add.

A project initiated by author Neal Stephenson as a resource first to annotate his novel Quicksilver, but based on the broader concept of a "metaweb" devised by Danny Hillis.

Downloadable song metadata--artist/album/track information--for audio CD and MP3 music players (Open Content License).

A volunteer-run open content encyclopedia.

Collaborative, peer-reviewed mathematics encyclopedia with TeX input, inspired by MathWorld (GNU Free Documentation License).

Collaborative resource on the history of computing and the Internet (GNU Free Documentation License), and the online companion to the book Technomanifestos.

A free encyclopedia built collaboratively using Wiki software. (GNU Free Documentation License).