Reading through their papers, while I didn't spend a lot of time studying the matter, I got the sense that the optimization strategies that Self employed would effectively accomplish similar types of optimizations, but arrive at them in a simpler and more general manner. As for a comparison with v8, I think v8, largely by eliminating bytecode, is a much simpler design and they are very well aware of the Self style optimizations that can be employed to make things go much faster than they do today. In other words, it's a simple design that already performs well (relative to other JS engines) and has lots of room for improvement. I only wish they had built the engine itself in a better language than C++. I'm not sure JavaScript would be a great language for building a VM, but I can think of at least one other language that would have been quite nice. ;)
- Stephen