The implications of using plug-ins are actually quite subtle and interesting. For example, MDLI Chemscape Chime has encoded internally some six chemical MIME types. When used as a plug-in, it appears to delete all these types from the options/general/helpers list that Netscape uses. The user does have the option of re-installing external helpers for chemical MIME, and these do take precedence over the plug-in definitions. What happens when for example two plug-ins both use the same MIME type is uncertain, largely because we have not yet found two plug-ins that address the same MIME type. The other aspect we are trying to resolve is that when the plug-in for a MIME type is not installed, and the HTML document references e.g a pdb file using an <embed> tag, Netscape invokes the following script; http://cgi.netscape.com/eng/mozilla/2.0/extensions/plugin.cgi?chemical/x-pdb Currently, Netscape have not implemented any info on chemical MIME, but when they do, some people might presume that this will act as the de-facto source of information on the topic. We are trying to find out if Netscape might be willing to put something useful to the chemical community into the response that http://cgi.netscape.com/eng/mozilla/2.0/extensions/plugin.cgi? produces. It is also possible to change the resource strings using an editor (such as ResEdit on a Mac) to redirect this to say; http://www.ch.ic.ac.uk/chemime/ but this runs the risk of contravening the Netscape license. We hope that the answers to these and other questions will be resolved shortly. If anyone has other thoughts/questions etc about the use of plug-ins in this context, do please send them to this list. Dr Henry Rzepa, Dept. Chemistry, Imperial College, LONDON SW7 2AY; rzepa@ic.ac.uk; Tel (44) 171 594 5774; Fax: (44) 171 594 5804. URL: http://www.ch.ic.ac.uk/rzepa/ ----- chemweb: A list for Chemical Applications of the Internet. Archived as: http://www.ch.ic.ac.uk/hypermail/chemweb/ To unsubscribe, send to listserver@ic.ac.uk the following message; unsubscribe chemweb List coordinator, Henry Rzepa (rzepa@ic.ac.uk)