> They send the sourcecode from the server to the client there is no time for a fully optimizing compiler.
The solution that the Dart VM and other JS VMs to is to compile twice: you do a very fast simple compile so that you can start executing code quickly and reduce start-up time. Then you find frequently-used functions and recompile them using a more advanced optimizing compiler. This is why many modern VMs have a "warm-up" period: code will get faster over time as it gets recompiled more optimally.
The solution that the Dart VM and other JS VMs to is to compile twice: you do a very fast simple compile so that you can start executing code quickly and reduce start-up time. Then you find frequently-used functions and recompile them using a more advanced optimizing compiler. This is why many modern VMs have a "warm-up" period: code will get faster over time as it gets recompiled more optimally.