What are some related communities online?

I think that it might be useful to create a list of related communities online that people might want to check out. Suggestions much appreciated.

Directly Related to rationalism

Skeptics Stack Exchange—useful for confirming factual claims you are skeptical of. Requires specific, answerable questions

Straight dope—similar to Skeptics, but less strict on the questions accepted

Change my view—place to get your view challenged

Cognitive Science—you are expected to do your reading first, but useful if your want to lean about what the research says

Philosophy Reddit

Rational Wiki: I only just learned about the existence of this site, so I don’t know how good it is yet

Secondary:

Stacks: StackOverflow, Computer Science StackExchange, Theoretical computer science, MathOverflow, Math StackExchange, Cross Validated, Physics Stackexchange

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