This chapter discusses and explores how Umbraco works under the hood. Umbraco's many features make it an especially efficient content engine. The most prominent feature is how it caches the content and makes it available at lightning speeds to the end user. This is all done using an XML cache and the .NET XSLT transformation engine.
If you want to extend the functionality of your XSLT output you can easily do so using XSLT extensions. Also, the .NET XSLT parser is based on the XSL 1.0 specification. Although you can extend your .NET installation using libraries, such as Saxon, to gain access to XSLT 2.0, there is a good chance that you do not need those libraries for working in Umbraco. Chapter 5 covers both XSLT stylesheets and XSLT extensions in depth.
This chapter also provides a detailed overview of the Umbraco backoffice, how and why it's set up the way it is, and best practices examples.