What’s cool? GitHub - EbookFoundation/free-programming-books: Freely available programming books
Tell me more!
This list was originally a clone of StackOverflow - List of Freely Available Programming Books with contributions from Karan Bhangui and George Stocker.
The list was moved to GitHub by Victor Felder for collaborative updating and maintenance. It has grown to become one of GitHub’s most popular repositories, with 271,000+ stars, about 9,700 watchers, more than 8,300 commits, 2,400+ contributors, and 54,000+ forks.
The Free Ebook Foundation now administers the repo, a not-for-profit organization devoted to promoting the creation, distribution, archiving, and sustainability of free ebooks.
Where is it?: GitHub - EbookFoundation/free-programming-books: Freely available programming books
This is one among many items I regularly tag in Pinboard as cooltech, and automatically autoshares as #cogdogcooltech to Twitter and Mastodon. Now the Coolness is in OEG Connect 
Have you ever been to Cool? Do you know of something cool I should share? Just reply below and I will check it out.