Well, in the mean time I wanted to have a look at process diagrams (emergency-service-core), by opening them in Eclipse (Indigo 3.7, where jBPM diagrams are usually ok).
None succeeded, throwing:
java.lang.IllegalArgumentException: Unknown model object null
at org.drools.eclipse.flow.ruleflow.editor.editpart.RuleFlowEditPartFactory.createEditPart(RuleFlowEditPartFactory.java:94)
at org.eclipse.gef.ui.parts.AbstractEditPartViewer.setContents(AbstractEditPartViewer.java:626)
at org.drools.eclipse.flow.common.editor.GenericModelEditor.initializeGraphicalViewer(GenericModelEditor.java:175)
at org.eclipse.gef.ui.parts.GraphicalEditor.createGraphicalViewer(GraphicalEditor.java:158)
at org.eclipse.gef.ui.parts.GraphicalEditorWithPalette.createPartControl(GraphicalEditorWithPalette.java:63)
at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:670)
at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:465)
at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
at org.eclipse.ui.internal.EditorReference.getEditor(EditorReference.java:289)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditorBatched(WorkbenchPage.java:2945)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2850)
at org.eclipse.ui.internal.WorkbenchPage.access$11(WorkbenchPage.java:2842)
at org.eclipse.ui.internal.WorkbenchPage$10.run(WorkbenchPage.java:2793)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2789)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2773)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2756)
at org.eclipse.ui.internal.ReopenEditorMenu.open(ReopenEditorMenu.java:296)
at org.eclipse.ui.internal.ReopenEditorMenu.access$2(ReopenEditorMenu.java:280)
at org.eclipse.ui.internal.ReopenEditorMenu$3.widgetSelected(ReopenEditorMenu.java:248)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:240)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4165)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3754)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2696)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2660)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2494)
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:674)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:667)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:123)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:344)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
at org.eclipse.equinox.launcher.Main.main(Main.java:1386)
Unfortunately no way even from the designer (in Drools-Guvnor), since the only way I know of to import into Guvnor is from Eclipse.