Recommend a good javascript statistics library?
Can anyone recommend a good javascript statistics library?

Perhaps one recommendation per question, and let the votes push the best to the top.  

note: 
Searching for javascript statistics seems lead one towards attempts at gathering statistics, I'm more interested in actual statistical calculations such as standard deviation and the like.
Recommend a good javascript statistics library?
===

Can anyone recommend a good javascript statistics library?

Perhaps one recommendation per question, and let the votes push the best to the top.  

note: 
Searching for javascript statistics seems lead one towards attempts at gathering statistics, I'm more interested in actual statistical calculations such as standard deviation and the like.