fixed forgotten ClInitRequired check in DateFormat - thanks to Jiri Vahala first stab at IntelliJ configuration. Note that the provided run configs require the 3rd party ContextRun IntelliJ plugin (https://github.com/m-lau/contextrun.git). The mapping uses a IntelliJ "project" per JPF project, and a IntelliJ "module" for each of the src/* subdirs (main, peers, classes,..). This is required to be able to set the subdir specific output dirs (build/main,...), which are in turn required to separate the jar contents and classpaths. We also keep the module definitions (*.iml) files under .idea and share the run configs, so that we can avoid any IDE content outside the IDE config dir. Separating the projects has also the silver lining that simultaneously opened projects are much better separated, which helps a lot if they contain the same class names. Note that the session specific .idea/workspace.xml is in .hgignore and hence doesn't get cloned/merged While this is all not the most IntelliJ compliant schema, the JPF directory layout can stay the same and Eclipse/Netbeans compatibility should not be affected.