Is there a decimal math library for JavaScript?

Is there a mature library for doing decimal-based math, possibly arbitrary-precision, in JavaScript?

Edit: I want this information for a reference page on floating-point-related problems and alternatives to use when binary floating-point is inappropriate: http://floating-point-gui.de/

As their author, I recommend bignumber.js or big.js, 'a small, fast Javascript library for arbitrary-precision arithmetic with decimal numbers'.

For a more mature library, the ICU4J BigDecimal translation is also recommended.

There's been a "port" of the Java BigDecimal class (I think it's here: http://freshmeat.net/projects/js_bigdecimal/ ) for a long time. I looked at it a long time ago and it seemed kind-of cumbersome and huge, but (if that's the one I'm thinking of) it's been used as part of some cryptography tools so there's a decent chance that it works OK.

Because cryptography is a likely area to generate a need for such things, that's a good way to snoop around for such packages.

edit: Thanks @Daniel (comment to question) for this older SO question: https://stackoverflow.com/questions/744099/javascript-bigdecimal-library