Our architecture is based on a central server sending XML data to the browser. The browser must make up its own data, and must understand XML (processing with javascript).
We have considered the use of XSLT but its was not yet stable at the time, so we have stayed with javascript parsers.
For sending data to the server we use the XMLHTTP object known only in IE and Mozilla.
Mozilla 1.7 now understands the onbeforeunload statement, which prevents loosing data while editing. So if you use Mozilla use that version.
For SVG part look in Adobe browser plug-in.
Support for Silverlight is currently in progress. It requires a considerable rewrite of current code and the results cannot be expected before 2009.
IE or Firefox can be used. We would like to support other browsers, so if you know another browser that supports XML and SVG we would appreciate your help (for example
we don't have a Mac to support Safari).
As Firefox supports native SVG, no plugin is needed.