> which you pay when using JVM or NET

Except Java and NET developers worth their salt are aware of ways to AOT compile their code to native, thus enjoying the same startup time as Go.

Is there a non commercial cross-platfornlm way to aot compile Java?

There used to exist GCJ, but its development died when the main developers joined OpenJDK development or moved elsewhere, back in 2009.

There is still the RoboVM version before it got acquired by Xamarin.

There are also Avian and JikesRVM, but it depends a bit what features you are using.

The problem with Java non-comercial AOT compilers is that the majority of the Java shops that really care about AOT compilation don't mind to pay for it, so there isn't a real effort to invest on a free AOT compiler.

The lack of community support for RoboVM was a good example of it.

Even the upcoming AOT compiler in the official JDK will be a commercial feature, at least it was announced as such.