In order to run, a Delphi application needs a lot of background information, such as how to interact with the operating system and how to create forms and components, such as buttons and edit boxes. This information is contained in various unit files that are a standard part of Delphi. This collection of units is referred to as the RTL (run time library). The RTL contains a very large number of functions and procedures for you to use.
Every routine is presented with a routine header and is described in a few to-the-point words, with sample code plus a link to some "real code" article. An Introduction to the .NET Framework Class Library article, the .NET Framework Class Library (FCL) consists of a series of classes, interfaces, and value types that can be used to program with.
This section of the About Delphi Programming site provides a through example-reference to the Delphi for .NET FCL capabilities. Every class is presented with a class declaration and is described in a few to-the-point words, with downloadable sample code (a console mode application). What's more, exactly the same source sample provided with MSDN are used (converted to Delphi language).