PocketStudio!

Free Pascal is a GPL'ed compiler that runs on Linux, Win32, OS/2, 68K and more. Free Pascal is designed to be able to understand and compile Delphi syntax, which is of course OOP. Lazarus is the part of the missing puzzle that will allow you to develop Delphi like programs in all of the above platforms. Unlike Java which strives to be a write once run anywhere, Lazarus and Free Pascal strives for write once compile anywhere. Since the exact same compiler is available on all of the above platforms it means you don't need to do any recoding to produce identical products for different platforms. »

Free Pascal (aka FPK Pascal) is a 32 and 64 bit professional Pascal compiler. It is available for different processors: Intel x86, Amd64/x86_64, PowerPC, PowerPC64, Sparc, ARM. The following operating systems are supported: Linux, FreeBSD, Haiku, Mac OS X/Darwin, DOS, Win32, Win64, WinCE, OS/2, Netware (libc and classic) and MorphOS.

CodeTyphon is a fork/distribution of Lazarus with thousands of Lazarus/Free Pascal components bundled into distribution and with own Lazarus expansion features.

Turbo Pascal is a software development system that includes a compiler and an integrated development environment (IDE) for the Pascal programming language running on CP/M, CP/M-86, and DOS.

The GNU Pascal Compiler (GPC) is, as the name says, the Pascal compiler of the GNU family,