I\'m using Eclipse as IDE and Maven outside of it to keep all dependencies up to date and update the Eclipse-project as such. In Eclipse I usually specify the JRE system lib
Since you are using maven and eclipse, perhaps you should use M2Eclipse plugin. The maven project (built by maven by setting JAVA_HOME=C:\Program Files\Java\jdk1.6.0_23) imported in Eclipse, shows up with JRE System Library as JavaSE-1.6