Interactive C is presently maintained by the KISS Institute, and is not available in source form.
There are, however, sources and binaries from an early version of Interactive C. This version has only a command-line interface (no GUI), and it does not include an integrated bootloader.
Thusly forewarned, here are the links.
- Interactive C for MS-DOS, configured for the Handy Board (280k .zip file)
- Interactive C for Mac OS 6, configured for the Handy Board (392k .hqx file)
- Interactive C for Unix (HTTP directory) The Unix version must be manually configured for use with the Handy Board. Please see libraries available in the Libraries page.
- Source code