Base2 is exactly what the title says,  Unlike the major libraries that strive to enhance javascript with shiny new features, Base2 strives to achieve a clean, browser independent execution environment.  In many ways base2 does for javascript what Blueprint, Tripoli et al. do for CSS.

Key Features:

• Inconsistent enumeration across platforms
• instanceof doesn’t always work
• typeof is inconsistent (RegExps identify as type “function” in Mozilla browsers)
• Consistent object/platform detection
• Other various bugs

And the sugar:

• A mechanism for inheritance
• A decent hash object
• Array and String generics
• Array extras
• Support for ISO date parsing

Playing with the library, it really is a breath of fresh air in many respects.  It’s lightweight (20kb compessed & 6kb) gziped and loaded with features that make day to day javascript development faster and easier.  Most importantly, it raises the bar for all browsers by providing Javascript 1.6 features to browsers other than Firefox.

You can get it online at

http://code.google.com/p/base2/ 

and there’s an excellent introduction at

http://dean.edwards.name/weblog/2007/12/base2-intro/ 

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