Apache's Jetspeed-2 Based heavily on several core Apache technologies, Jetspeed is a very open and customizable portal platform (portals.apache.org/jetspeed-2)

Exo Platform An open-source Java-based portal system that is less mature but very similar to Liferay (www.exoplatform.com)

JBoss Portal A user-friendly open-source portal based on Java from one of the top Java application server vendors (www.jboss.com/products/jbossportal)

Magnolia Organization's Magnolia An open-source, Java-based CMS that puts a high premium on usability, with a very good user interface (www.magnolia.info)

The Plone Foundation's Plone An eWEEK Labs' Analyst's Choice winner, this open-source product is one of the best solutions, period, for company portals and intranets (www.plone.org)

Labs Director Jim Rapoza can be reached at jim_rapoza@ziffdavis.com.

This article was originally published on eWEEK.com.