The best replacement for glassfish is jboss.

The best alternatives to glassfish are rated as following:
★★★★★  jboss
★★★★★  tomcat
★★★  weblogic
★★  apache
★★  geronimo
★★  wildfly
★★  websphere
★  apache tomcat
★  jetty
★  tomee
  sun application server
  tomcat server

Your alternative for glassfish is not listed? Suggest!
Speaking about glassfish, one probably shouldn't forget about netbeans.

Other search terms related to glassfish and their ratings are:
★★★★★ netbeans
★★★ jdk
★★ activemq
openjdk
You have in mind a companion for glassfish and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of glassfish in all years. Click on graph for more.
glassfish
jboss
tomcat