Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Free Pascal (FPC for short, and formerly known as FPK Pascal) is a free, portable and open source compiler for Pascal and Object Pascal languages. It supports a number of dialects, including the two most popular Borland dialects—Turbo Pascal and Delphi—and some Mac Pascal constructs. Free Pascal is available on many architectures and operating systems (see Targets), and belongs to the write once, compile anywhere campaign. It has an excellent support for integration of assembly language, and supports multiple architectures and notations in the internal assembler. With a separate IDE project called Lazarus, cross-platform graphical application development is possible with little effort.