I completely agree -- I'm not about to start using it for real projects, it's really just a thought experiment about how nice JavaScript could be with an alternative syntax.
That said, if you work with Ruby and want to play with compilers, check out CoffeeScript's source. It's got a clean Ruby lexer and Racc parser (examples of which are hard to find in the wild) -- the code generation is a little funky, but I'm hoping to clean that up. The whole shebang is under 1500 LOC, including comments, so it's not too much to wrap your head around.
That said, if you work with Ruby and want to play with compilers, check out CoffeeScript's source. It's got a clean Ruby lexer and Racc parser (examples of which are hard to find in the wild) -- the code generation is a little funky, but I'm hoping to clean that up. The whole shebang is under 1500 LOC, including comments, so it's not too much to wrap your head around.