Since you can no longer get a zip file from GateIn’s website, I’ve cloned their GIT repo.
1) Add the Java repositories
apt-get install oracle-java7-installer
2) Install GIT and clone the repo
apt-get install git
git clone git://github.com/gatein/gatein-portal.git
3) You will also need Maven, Ant, and Tomcat7
apt-get install maven ant tomcat7 antlr3-gunit-maven-plugin libmaven-shared-io-java-doc libmodello-jav
4) Issue the command to build GateIn. In this case, I want my portal to answer to http://www.myserver.com/web/….. If you want something similar you must create the directory first.
mvn clean install -Dgatein.dev=tomcat7 -DskipTests -Dservers.dir=/var/lib/tomcat7/webapps -Dserver.name=/web
5) It finished the build, but I’m still not able to get it to function. Either tomcat dies or exo never lives. Either way, it’s not much to go on.