Your membership fee helps pay our authors and other operating costsSee membership benefits
Donate any amount - everything counts!
Post a link on Facebook, Twitter, LinkedIn, or another social service to spread the word about us. Here's the button:
We are highly selective of which authors we invite. Please help us by nominating an author who has made a great impact on your professional or academic career.
Direct unsubscription link in every email
This will help spread the word about our daily quote service:
It's really hard to design products by focus groups. A lot of times, people don't know what they want until you show it to them.
-- Steve Jobs, 1998
People from around the world show their support for our mission to make world-class educational materials available for free. It's all about the Democratization of Knowledge.
Get creative and add your picture!
This site is huge and it may take months to discover a typo, grammar error, technical problem, bug, etc.
If you find one please tell us at once! If not, it may continue to annoy visitors like yourself for a very long time.
Add your favourite thoughtful quote to our extremely popular quote-of-the-day collection.