Philosophy Encyclopedias

Here's a couple of very good free online philosophy encyclopedias. Each consists of entries written by professional philosophers, often big names, and are peer reviewed. Each has its own strength.

The Internet Encyclopedia of Philosophy. This one seems to me to be more comprehensible to those new to the topics.

http://www.iep.utm.edu/

The Stanford Encyclopedia of Philosophy. This one can be more technical, seemingly written for philosophy professionals.

http://plato.stanford.edu