While working on XML serializers I wandered into the XSLT land. It turned out that XSLT support in .NET is not stellar. Well, you may already know that, but it is new to me. First, only XSLT 1.0 is supported. It is useful for simple stuff, but even an iteration over a list of known values is difficult. There are two classes for XSLT in .NET: an obsolete class XsltTransform and a newer XsltCompiledTransform. Both of them are XSLT 1.0, the latter been allegedly faster and more secure (read: more items disabled). E.g. you cannot use document() function by default. Overall, I am disappointed. I wanted to use XSLT for simple things like show summary and results of XML serialization calls, and it turns out I have to use XSLT 2.0 (distinct-values) or non-standard stuff like node-set for even the simplest things.