jenkins mountain lion server
After reading the https://wiki.jenkins-ci.org/display/JENKINS/Meet+Jenkins page where an easy installation was mentioned (java -jar jenkins.war) I remembered that java may not have been installed by default on a clean Mountain-Lion Server.After activating the terminal and typing:
server:~ ioscoder$ java -vNo Java runtime present, requesting install.it asked me if I wanted to install java. After accepting this and performing an installation of java, I was happy to see the 'Dashboard [Jenkins]' page in Safari for the localhost:8080.