Tomcat's release numbers coincide with the servlet and JSP releases (the numbers don't match but there is a table on the front page of the Tomcat site showing how they correlate).
Tomcat is an open source project. Weblogic is a commercial product.
It's not reasonable to ask someone to sit and list the differences between these products. If you're trying to decide between the two, you will need to sit with the literature and figure out which is best suited for your project.
Since Weblogic is a commercial product that you will be paying for, you could probably get one of BEA's salespeople to read the literature for you and tell you why Weblogic is better than Tomcat.