The requirement for Netscape Navigator is because Netscape invented plugins and javascript. Chime is a plugin and these pages make heavy use of javascript. Until Internet Explorer (IE) implements full plugin and javascript support, these pages will not work with IE. It appears likely that IE will provide this support in the near future. The failure of Chime to work with IE is not the result of a policy of MDL Information Systems, Inc. (the creators of Chime), but an unavoidable consequence of the fact that Chime is a plugin.