When Oracle stopped the commercial support for GlassFish, there had been an exodus to WildFly and other servers. WildFly works fine with NetBeans, and I blogged how to install application servers with NetBeans .
GlassFish is still used for the reference implementation of Java EE technologies. To be on the bleeding edge, you might get GlassFish 5 nightly builds .
If you want to stay productive with GlassFish 4, there is an free alternative which offers intensive support too. Payara is an application server derived from GlassFish 4.1 . If you want to give it a try, simply download the zip file of payara server and unzip it to a folder of your choice. Within NetBeans, choose tools, add server and add it as GlassFish server. The installation procedure is quite the same as described in my former blog entry .