If you see a "3rd edition" file on GitHub or elsewhere, it is likely one of the following:
A popular book by Jens Gustedt that covers the latest C23 standard . The C Programming Language 3rd Edition Pdf Github
Brian Kernighan and the late Dennis Ritchie never updated the book to cover standards beyond C89, such as C99, C11, or the current C23 standard . If you see a "3rd edition" file on
Instead of a new edition, other authors have stepped in to cover modern standards like C11 and C23. Common Sources of Confusion such as C99