Microsoft Visual C++ 2010 Express
This is available along with the other tools in the Microsoft Visual Studio 2010 Express suite. It can be downloaded for free with registration required within 30 days.
GCC - the GNU Compiler Collection
GCC, the GNU Compiler Collection, includes front ends for C, C++, Objective-C, Fortran, Java, and Ada, as well as libraries for these languages (libstdc++, libgcj,...).
Dev C++ is a development environment that comes with the free GCC compiler (MingW port) included and is a good compiler package for those programming on Windows-based computers. Dev-C++ can also be used in combination with Cygwin or any other GCC based compiler.
A Free C Compiler System For Windows 95/98 and NT.
A complete 32-bit C/C++ development system for Intel 80386 (and higher) PCs running DOS. DJGPP is a compiler and a set of tools that let you produce 32-bit protected-mode programs which run on MS-DOS/MS-Windows machines.
The Cygwin tools are ports of the popular GNU development tools and utilities for Windows 95 using the Cygwin library which provides a UNIX-like API on top of the Win32 API. With these tools installed, it is possible to write Win32 console or GUI applicat
MinGW is a collection of header files and import libraries that allow one to use GCC and produce native Windows32 programs that do not rely on any 3rd-party DLLs. The current set of tools include GNU Compiler Collection (GCC), GNU Binary Utilities (Binuti
Digital Mars C and C++ Compilers for Win32, Win16, DOS32 and DOS.
Apple's Developer's Workshop
C and C++ compilers.
A C Programming Environment for the Macintosh made specifically for learning the C language, visually debugging C programs, and creating algorithm animations in a declarative style. .
Small Device C Compiler
SDCC is a freeware, retargettable, optimizing ANSI C compiler. The current version targets the Intel 8051 and recently the Zilog Z80 based MCUs. SDCC can be retargeted for other 8 bit MCUs or PICs.
CINT C/C++ Interpreter
CINT is a C/C++ interpreter which is aimed at processing C/C++ scripts.
Sun Studio Compilers and Tools
Available for Solaris and Linux with an IDE and tools and compilers for c, c++ and fortran.
The OnBoard C compiler creates a Palm executable or (at the programmer's option) a Hackmaster hack. You can beam your new program or hotsync it to another Palm if you like. It requires nothing but a Palm (w/ the Palm OS in ROM so your code can take advantage of the library that's there). It does not need a separate run-time library.
Pelles C for Windows is a complete development kit for Windows and Pocket PC. It contains among other things a optimizing compiler, a linker, a resource compiler, a message compiler, a make utility and install builders for both Windows and Pocket PC. It also contains a integrated development environment (IDE) with project management, debugger, source code editor and resource editors for dialogs, menus, string tables, accelerator tables, bitmaps, icons, cursors, animated cursors, animation videos (AVI's without sound), versions and XP manifests. The compiler is based on LCC, and the install builder for Windows is based on NSIS. Both are heavily modified.
A small C compiler for Linux.
Ch C/C++ Interpreter
Ch is a powerful C/C++ interpreter. It supports classes in C++ and many new features in the latest C99 standard. The industry standard POSIX, X11/Motif, OpenGL, ODBC, XML and GTK+ are supported as well. Ch has built-in graphical support and can be run acr
Cyclone is a programming language based on C that is designed to be safe, meaning that it rules out programs that have buffer overflows, dangling pointers, format string attacks, and so on. The Cyclone compiler and tools, as well as some benchmark programs, are freely available for download.
HP-GCC - a C compiler for HP calculators
HP-GCC is a suite of programs that allow you to program ARM-based HP calculators in C. Being released under the GPL, it is free to use and modify. HP-GCC is a project aiming to make advanced programming in C easy.
z88dk - The z88 Development Kit
z88dk is a z80 C cross compiler supplied with an assembler/linker and a set of libraries implementing the C standard library for a number of different z80 based machines. z88dk is known to run on the following platforms: Amiga, BeOS, HP-UX 9, Linux, MacOS X, Solaris, Win32, Win16 and MSDOS. Binary releases are available for Amiga, Solaris and Win32.
Open Watcom is a joint effort between SciTech Software Inc, Sybase, and the Open Source development community to maintain and enhance the Sybase Watcom C/C++ and Fortran compiler products.
Compaq C Version 6.2
Compaq C for Linux Alpha is now available for immediate download upon acceptance of license terms and filling out an online registration form.
TenDRA is a free, public domain C/C++ compiler and checker technology, developed by the Open Software Systems Group (OSSG) at DERA around its TDF/ANDF compiler intermediate format.