Actually ASP.NET's asp:xml server control has a long story of suckiness on XSLT. In .NET 1.X this control, whose main goal is to perform XSLT transformations server-side didn't support XPathDocument, which is recommended (by Microsoft itself) XML data store for XSLT. In .NET 2.0 thanks this issue is rectified, but now it doesn't support new Microsoft .NET XSLT processor!
Anyway, what about a better ASP.NET XML server control? The one that's fast and conformant by using new XslCompiledTransform, supports XInclude and EXSLT.NET? I believe we at the Mvp.Xml project can do it easily, would you use it then?
Eclipse is hot nowadays. With BEA, Borland, CA, HP, IBM, Intel, Nokia, SAP, Sybase etc behind it, Eclipse is becoming "the development platform" for modern programming. And what's interesting - Eclipse is fully driven by corporate vendors, ISVs, start-ups and individual hackers extending and improving the Eclipse platform, which is of course open-source. Eclipse was designed to be community driven and this time it seems to be working.
IBM's Java IDE I'm working with when I do Java is of course just Eclipse with a bunch of plugins from IBM and this is the best Java IDE I ever seen.
Be Eclipse and Visual Studio competitors I'm not sure I would bet on Visual Studio. But actually Visual Studio users benefit from Eclipse too! I believe the raise of Eclipse was the main reason why Microsoft introduced express SKUs and made the VSIP program (Visual Studio extensibility API, now Visual Studio SDK) free for everyone. Now it sounds ridiculous, but just couple years ago one had to pay $10K/year to Microsoft just to be able to write a tool based on Visual Studio. Now everybody can do it for free and you'll see more and more Visual Studio based third-party tools.
Unfortunately Visual Studio is not open source, poorly documented and is based on old weird legacy layered in a complicated way code, mosty COM with more and more C# via interop so extending Visual Studio is still not easy. The next next next version of Visual Studio codenamed Hawaii being probably the complete redesign is only our hope for better Visual Studio.