GlassFish became the Killer Appserver. GlassFish was one of the favorites in green field Java EE projects--the vast majority of my clients used GlassFish in production in 2013.
The C2B2 company offered commercial support in late 2013. During JavaOne 2014 a "New Fish On The Block"--Payara was announced. Payara is a GlassFish 4.1 clone maintained at https://github.com/payara/Payara, heavily patched and further developed by the community.I'm closely watching Payara since JavaOne 2014. Some observations:
- Developers behind Payara are present at major conferences (JavaOne, Devoxx). C2B2 (the company behind Payara) organizes vibrant London GlassFish User Group meetings and events
- Payara's developers are highly skilled and focussed, but open for contributions at the same time
- Payara community is very responsive and reacts quickly to issues
- The first binary release is available http://payara.co/downloads with fixes and interesting enhancements (e.g. hazelcast integration)
- A few hundred commits were already contributed by the Payara's community is used since JavaOne 2014
- Payara is as open source as GlassFish--the same license
- Payara is lean, clean and easy to install
- Payara's branding is appealing (never underestimate marketing)
- Effectively Payara is Java EE 7 compliant, commercially supported, application server.
A small issue: caused by higher version number, NetBeans currently does not recognize Payara as GlassFish. The issue is already addressed and can be easily fixed by renaming a JAR in the distribution:
mv glassfish/lib/install/applications/__admingui/WEB-INF/lib/console-core-4.1.151.jar glassfish/lib/install/applications/__admingui/WEB-INF/lib/console-core-4.1.jar