Would you consider Lua fits those requirements? The reference manual is short, the online guide and book simple to follow, and the syntax consistent.
However, it's ridiculous that I cannot easily just use Lua for browser applications!
Sorry. That's a deal-breaker. Even if I concede that 1-based is a style choice you can get used to (and I do not), you must interoperate with the land of C and that is all 0-based.