I think you mean 'JBoss AS' and 'JBoss EAP', this is technical (more or less) the same.
The difference is:
- AS is the community edition
- no professional support
- open source
- new features
- EAP is the enterprise edition
- professional support
- tested before released
- only stable features included
If you mean with 'on the same server' the same physical machine, yes you can but I would recommend that you do not use it in a cluster, the behaviour might different in some cases.
Thanks, can we say that Application server is just a subset of EAP? And how do you call the "jboss-5.1.0.GA folder" in AS installation? Web server? Application Server? EAP sounds more comprehensive and containing things such as Messaging, framework etc
And if I have the AS installed, can I install EAP under a separate folder and make things work? I am not sure if there would be impact in setting environment variables such as JBOSS_HOME etc, I have no plan to do clustering because I am only just setting my development box, but like to know how I can make things work for both EAP and AS environment
No (community) Application server is the open source variant.
The EAP server is the full supported variant by professional (paid) support.
The functionality is mostly the same, both are full JEE server!
You might install as much (different) JBoss instances in parallel as you want.
I would set no JBOSS_HOME because the start script use it's installation path. Otherwise you might have unexpected results because if jBOSS_HOME is set the run-script will use this location.
Physically, EAP = AS + patches-to-AS + Seam-runtime
That should help explain the subdirectories under jboss-eap-*
And I'll repeat Wolf-Dieter's recommendation: NEVER set JBOSS_HOME, especially if you plan to have multiple JBoss AS instances.