HiC, developed by Robert W. Hasker, is freely available for use by institutions of up to 15,000 students for on-campus (traditional) courses, though instructors should contact the author to get on a mailing list for updates. This mailing list will have very low traffic, and email addresses will not be shared with commercial organizations under any circumstances. Larger institutions, and instructors and students of online/distance courses must contact the author for permission to use HiC. Professionals should be using a professional compiler!
Note that HiC is supported for Windows/Intel platforms only. It runs on all 32-bit and 64-bit Windows systems including Windows 95, 98, NT, ME, 2000, XP, Vista, and Windows 7. For other platforms, see here.
In most cases, you should be able to download and run HiC.exe directly. There is no installation needed (there are no separate library files), and you can place the application in whatever folder you wish, including the desktop.
Some Windows 95 systems will have difficulty running HiC. If you see the message to the effect of "Assertion failed: textHeight > 0, file C:\hic\MainWin.cpp, line 114", this means you don't have the "RichEdit" DLL HiC needs installed on your machine. To fix this, download and execute Riched30.exe; HiC should then run without problems. You should be able to get Riched30.exe by searching the internet.
Once HiC is up and running, using it should be pretty self-explanatory for people who know C++. In particular, see the help menu for a syntax of the C++ subset that is supported and descriptions of what libraries are supported. Remember, you get what you paid for: the system is not guaranteed to compile programs correctly and there is no warranty.
HiC contains support for programming LEGO Mindstorms RCX Robots. See here for further information.