Could you clear in what aspects Glassfish and Tomcat are similar and what Glassfish features aren't founded in Tomcat?

Glassfish has features? Are you kidding?
It is very unstable (even in its home base net beans) and should be considered a marketing vehicle for more expensive weblogic line-up.
It is java ee implementation that adds couple of libraries on top of JSP implementation which is Apache Tomcat.
Indeed TomEE+ is apache project that bundles ear unzipper and those libraries with tomcat.

What you asked and the way you asked - by analogy - How IIS compares to ASP.

I'm still waiting a neutral and only tecchnical reply about my question.

You are comparing apples and oranges
Glassfish is the reference Java Enterprise Environment
only Tomee, note: this is tomcat with Enterprise Environment Extensions, supports the java Enterprise Environment but not full version 7 compatibility.
https://en.wikipedia.org/wiki/Comparison_of_application_servers

You are comparing apples and oranges

I don't think so
Glassfish IS a web application container (like Tomcat)

In some features they are interchangeable, accordinlgy with:

My question is:

Could you clear in what aspects Glassfish and Tomcat are similar and what Glassfish features aren't founded in Tomcat?

and I add: and vice versa.

What are you trying to achieve?
Glassfish is effectively EOL
http://www.zdnet.com/article/oracle-abandons-commercial-support-for-glassfish-jee-server/
TomEE implements Java EE 6 Web profile.
Whats missing?
https://en.wikipedia.org/wiki/Java_EE_version_history#Java_EE_7_.28June_12.2C_2013.29
Dozen of libraries, that you can download reference implementation IF you really need them.

Hi Gheist

I guess now I better understand what you means

Glassfish -  Web Container/ Java EE6 is a reference (maybe for conceptual guidance purposes) server and is at end of line.  The correct server to use now going Oracle is WebLogic.

TomEE - Web Container (Tomcat)  /  Java EE is the option going Sun option.
If any other library is needed to complete any specific task  it could easily be downloaded.

Isn't it?

You might find this direct comparison between Glassfish and Tomcat from the IT Central Station user community to be helpful: https://goo.gl/zFfgXr.

As mentioned already in the comments, users interested in these solutions also read reviews for Oracle WebLogic Suite. This user writes, "I have used many application servers, and this is the best for performance and for a user-friendly management console.” You can read the rest of his review here: https://goo.gl/LQAzOE.

Thank you Danielle