Free Pascal is a professional but free 32 bit / 64 bit compiler for Pascal and ObjectPascal. It supports a wide variety of processors and Linux distributions including the Raspberry Pi.
It can target multiple processor architectures including Intel x86, AMD64/x86-64, PowerPC, PowerPC64, SPARC, and ARM. Supported operating systems cover Linux including Raspbian, FreeBSD, Haiku, Mac OS X/iOS/Darwin, DOS, Win32, Win64, WinCE, OS/2, MorphOS, Nintendo GBA, Nintendo DS, and Nintendo Wii. Additionally, JVM, MIPS (big and little endian variants) and Motorola 68k architecture targets are available in the development versions.
Free Pascal may be invoked at the command line or it may be used via Lazarus, a graphical IDE.