These are free online C-Compilers available on other sites. These compilers will use a modern version of the C syntax so you might get warning errors when you compile the code directly from the 1978 edition of the book.
Please let me know if this list should be updated. You could even edit the the source code for this file and send a GitHub Pull Request.
Original materials in this site are Copyright Creative Commons Attribution 4.0 - Charles R. Severance. Other materials remain copyright of their original owners.