But don't you agree that Weld should look for classes also in the parent application ClassLoader?

I'm not sure this is only about CL. Anyway, we should consider this feature request . BTW this is also discussed in the scope of CDI 2.0 - see also https://issues.jboss.org/browse/CDI-529.

Without such feature, running Weld on the exploded archive won't be possible without keeping exactly the same version of the beans.xml inside two locations - which is basically an ugly hack.

I believe the exploded archive would work fine. The problem is running the app from the source dir/IDE.