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.
Mozilla's Firefox browser has quickly become a very popular web browser. Java is fully supported by Firefox via the Java Plug-in for Firefox. To properly run Java applets you must also install Java 6 Update 15 from Sun Microsystems. Firefox runs on all major desktop platforms.