Mozilla has reached an important Milestone as its new JavaScript engine “JaegerMonkey” is now faster than the current “TraceMonkey” in a key benchmark. Mozilla wants JaegerMonkey to be faster than the competition and launch on September 1, which means that JaegerMonkey will make it into Firefox 4.0.

It isn’t faster by much and it is only faster in the V8 benchmark 6829 ms vs. 6841 ms. In Sunspider, JaegerMonkey is still behind TraceMonkey – 754 ms vs. 718 ms. The new engine is well behind the competition as well: The Webkit browsers Chrome and Safari are below 400 ms and Google is even close to break the 300 ms mark. Opera is also in the low 300s.

When JaegerMonkey was first announced earlier this year, the goal was to hit 500 ms in Sunspider. That isn’t good enough anymore as even Microsoft’s IE9 is now below 500 ms. Mozilla still says that JaegerMonkey’s goal is to be as good or better than the competition, which means that Mozilla has to aim for 300 ms straight.

The good news is that JaegerMonkey does not carry any baggage as it is written from scratch and the improvements Mozilla has made over the past 8 weeks is considerable. Mozilla said that it is “generating pretty good machine code at this point.”

However, the schedule is somewhat tight: “Over the next six weeks, we’ll be polishing JägerMonkey in order to land by September 1,” Mozilla said. And there is a lot left to do as JaegerMonkey has still weaknesses. For example, its function calls are about “10X slower than the competition,” Mozilla said.