The final version of Firefox 3.0 doesn't play well with the first version of Microsoft's Adobe Flash killer. The faulty integration between Mozilla's latest iteration of the Firefox open source browser and Silverlight 1.0 is caused by a bug which has survived all the way into Firefox 3.0. Mozilla is aware of the issue, revealed Nigel Parker, Microsoft Developer Evangelist, but let Microsoft deal with it. As far as the Redmond company is concerned, Silverlight 1.0 is already a thing of the past, with the focus now on version 2 of the technology.

"Firefox 3 has a condition that affects the way that < object is invoked, loaded and detected," Parker explained. "What this means is that the forthcoming Firefox 3 release will break some Silverlight 1.0 installation experiences on web sites that used the original Silverlight 1.0 SDK Silverlight.js detection file. The Silverlight 2 SDK has an updated Silverlight.js file that not only solves this problem for all versions of Silverlight but also eliminates browser restart that was previously needed for new installs."

Silverlight 2 no longer produces content which will break in Firefox 3.0. Microsoft has made available for download Silverlight 2 Beta 2 since the second week of June. The software development kit served concomitantly with the browser plug-in no longer features the problematic Silverlight.js. Developers that have used Silverlight 1.0 SDK in order to produce content are advised to update to the Silverlight 2 Beta 2 SDK and deal with the issue. But, at the same time, there are additional mitigations designed to resolve the problem.

"If you want to link to the Silverlight.js file hosted at Silverlight Streaming (best practice) the one to use is here. Also you can now invoke Silverlight Streaming applications without using JavaScript at all. We support a URL syntax that directly names a self-contained web page with nothing but your Silverlight Streaming-hosted application. You can use this URL as the source of an < iframe > tag to embed the application on sites that don't allow JavaScript," Parker added.

Here are the downloads for Silvelight 2 Beta 2 from Softpedia:

- Microsoft Silverlight 2.0.30523.6 Beta 2
- Microsoft Silverlight 2.0.30523.6 SDK Beta 2
- Microsoft Silverlight Tools Beta 2 for Visual Studio 2008 2.0
- Microsoft Expression Blend 2.5 June 2008 Preview.