If you don't need the memory savings, you probably want to start migrating to ruby 1.9 for the speed improvements. JRuby is also a good alternative. (faster tha

If you don't need the memory savings, you probably want to start migrating to ruby 1.9 for the speed improvements. JRuby is also a good alternative. (faster than 1.8, OS-level threads) So no reason to not use REE, but there are other alternatives that have their own strengths.