JRE should be adequate for running Magnolia CMS (MGNLEE-135). JDK is not needed unless you want to debug. Even the installer accepts a path to JRE.

Issue is, when you set the path in the installer to a JRE location and start Magnolia, it warns "JAVA_HOME should point to a JDK not a JRE".

Details:

• Installation documentation says that JRE is adequate.
• The issue is reported by Windows users. (1, 2)
• Per Ondrej:
  • JRE is not enough for Magnolia nor Tomcat (7.0.22)
  • When both JRE and JDK are installed and JAVA_HOME is pointing to JRE, Magnolia is still complaining but Tomcat is working.