They make up the cardiac pacemaker, that is, the natural pacemaker of the heart. In most humans, the concentration of pacemaker cells in the sinoatrial (SA) node is the natural pacemaker, and the resultant rhythm is a sinus rhythm. Sometimes an ectopic pacemaker sets the pace, if the SA node is damaged or if the electrical conduction system of the heart has problems.
Lobo is an extensible all-Java web browser and RIA platform. It supports HTML 4, Javascript (AJAX) and CSS 2 plus direct JavaFX and Java (Swing/AWT) rendering. Cobra is the web browser's renderer API; also a Javascript-aware HTML parser.
The official word from Oracle appears to be that they aren't going to do it: Chrome no longer supports NPAPI (technology required for Java applets) The Java plug-in for web browsers relies on the cross platform plugin architecture NPAPI, which has been supported by all major web browsers for over a decade.