Interestingly enough, the first live.com hit for the "XslCompiledTransform Performance" query at the moment is this post of Jeff Prosise, where he says he was disappointed that XslCompiledTransform ran just 3 times faster than XslTransform on a "fairly simple style sheet". He is concerned that XslCompiledTransform is not fast enough comparing to the good old MSXML 4.0. Well, as we will see very soon, XslCompiledTransform may easily outperform MSXML 4.0 by several times!

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The .NET Framework 2.0 provides a new System.Xml.Xsl.XslCompiledTransform XSLT processor class, which is intended to replace the obsoleted XslTransform class. One of the major differences between the two is that while the latter is an XSLT interpreter, the former is a real XSLT compiler, allowing significantly faster execution times. Does it mean XslCompiledTransform is always faster? Surprisingly, the answer is not that simple....