Fyi, APACHE/BSD/MIT licenses are recognized free software licenses taht allow the code to be included in any software (even commercial) with the only restriction NOT to use the author name as a trademark, and to keep in source code the original copyright notices.

The issue with “0″ is for formating 4 -> “4″ and 4.1 -> “4.1″ with the same pattern. From your test cases :

-> 4.5, “0.00″, “4.50″, // OK : fixed number of decimals
-> 4, “0.#”, “4.0″, // I expected : “4″ # should be for optional

I don’t have time to look into the details of licensing right now, and I would need to understand the other licenses deeply to make that decision. You could dual-license your project if you wish.

I’m unclear from your description whether the 0′s are necessary. If you don’t want them, you can use “#.” instead, right? What use case doesn’t the existing behavior support? It’s supposed to be compatible with existing standards, so if it’s not, a test case and patch would be great.

your number formatting helped me lot. I just have two considerations :

- about licensing, could you double license it under LGPL and BSD/MIT or APACHE ? I’m writing an Apache-licensed project, and cannot integrate your lib as is due to licensing considerations.

- did you test your lib with Prototype ? I didn’t tested myself but I thing it may conflict with http://www.prototypejs.org/api/number.