Implementation components used by various Java EE servers
There are quite a lot of Java EE server implementations out there. There are a bunch of well known ones like JBoss, GlassFish and TomEE, and some less known ones like Resin and Liberty, and a couple of obscure ones like JEUS and WebOTX. One thing to keep in mind is that all those implementations are not all completely unique. There are a dozen or so Java EE implementations, but there are most definitely not a dozen of JSF implementations (in fact there are only two; Mojarra and MyFaces). Java EE implementations in some way are not entirely unlike Linux distributions; they package together a large amount of existing software, which is glued together via software developed by the distro vendor and where some software is directly developed by that vendor, but then also used by other vendors. In Java EE for example JBoss develops the CDI implementation Weld and uses that in its Java EE servers, but other vendors like Oracle also use this. The other way around, Oracle develops Mojarra