Tomcat - which version?

Newbie question. What is the difference between the two Apache Tomcat versions? Tomcat-native and Tomcat5? I want to create some Java servlets. Mac OS-X Tiger 10.4.8 Second question: I tried to "port install Tomcat5" and it failed due to inability to find Ant-1.6.5. Apparently all the mirrors now carry only Ant-1.7? Is there a way to tell it to use the newer Ant, or should the portfile be updated? Or is there an old 1.6.5 somewhere? Thanks in advance, --david