Installing a servlet container is NOT needed to run Cocoon

Despite what some urban legends say, you do not have to install a servlet container before running Cocoon, as the distribution includes a subset of Jetty that is sufficient for testing or simple development purposes.

If you just want to test Cocoon or play with the samples, you only need a JDK to build and start Cocoon. See the INSTALL.txt file in the Cocoon distribution, or the How to run and explore the Cocoon samples page.