On October, 1st 2016, NetBeans became an official Apache Incubator project. A full list of all incubator projects is available at . I assume that the project page (which is quite shortly today) will present much information soon .
A description of the incubation process is available at the web, too .
Some projects stay in the incubator for quite a long time. Since NetBeans is a very matured project, I hope it will become an Apache top level product soon.