The Free Pascal Compiler is a Turbo Pascal 7.0 and Delphi-compatible 32/64 bit Pascal Compiler. It comes with a fully TP 7.0-compatible run-time library. Some extensions have been added to the language, like function overloading. Shared libraries can be linked. Basic Delphi support is implemented with classes, exceptions, RTTI, and ansistrings. A Free Component Library (FCL) is available with the base classes. Bindings for X11, ncurses, GTK, OpenGL, zlib, mysql, interbase and postgres are available.
The Amsterdam Compiler Kit is a fully-featured retargetable compiler toolchain. It will cross-compile ANSI C, K&R C, Pascal, Modula-2, Occam, Fortran and Basic for a number of architectures including, but not limited to, the 6500, 68000, Z80, i80, i86, i386, and PDP-11. It provides a complete development environment including preprocessors, compilers, assemblers, linkers, librarian tools, and target download tools.
Pascal-P4 for Free Pascal and Delphi is a port of a Pascal compiler written at ETH Zurich in 1976. The source code of the compiler is documented in the book "Pascal Implementation" by Steven Pemberton and Martin Daniels. The purpose of this project is to make Pascal-P compilable by Free Pascal and Delphi while keeping the changes to a minimum and preserving the line numbering as much as possible.