An event library for JavaScript and Node.js that implements the observer pattern (a.k.a publish/subscribe). Similar to Node's EventEmitter and Backbone.Events, but independent, minimal and light-weight.
Testing and assertion library with friendly BDD syntax — awesome.must.be.true(). Many expressive matchers and is test runner and framework agnostic. Follows RFC 2119 with its use of MUST. Good and well tested stuff.