Wiki encyclopedia project in which authors use their real, verified names and recognized subject experts can guide the development of citable articles.
Connected: An Internet Encyclopedia
The engineering, theoretical concepts, and organizations of the Internet (freely distributable).
Ekopedia is an encyclopedia about alternative life techniques with strong focus on ecological impact.
An extensively hyperlinked collection of facts, ideas, notes and humor to which anyone can add.
A volunteer-run open content encyclopedia.
Collaborative, peer-reviewed mathematics encyclopedia with TeX input, inspired by MathWorld (GNU Free Documentation License).
An open wiki for statistical mechanics and thermodynamics.
Wikipedia Article - Nupedia
Nupedia was a public peer-reviewed general encyclopedia created by volunteer scholars, with resources for readers and contributors (GNU Free Documentation License). It can be considered to be Wikipedia's direct ancestor.