OpenBSD
- OpenBSD : Official home page of OpenBSD
- OpenBSD Ports : Database of all OpenBSD ports
- marc.info : Collection of OpenBSD mailing lists
- OpenBSD Journal : OpenBSD related news and information
- M:Tier : Packages for OpenBSD -stable releases
- RunBSD : User stories from {Open,Net,Dragonfly,Free}BSD users
- Daemon Forums : Message boards for the various BSDs
Blogs
- Paul Graham : Essays from the Y Combinator founder
- Grenadille : OpenBSD developer Martin Pieuchot
- JCS : OpenBSD developer Joshua Stein
- poolp.org : OpenBSD developer Gilles Chehade
- ReykFloeter : OpenBSD developer Reyk Floeter
- Vermaden : Unix sysadmin running FreeBSD
- Trivia : Linux sysadmin running Debian
- HiR : Security, programming, and system administration
Books
- Computer Science from the Bottom Up : OS fundamentals through to application compilation and execution
- Programming from the Ground Up : Introductory book to programming and computer science using assembly
- How to Design Programs (2nd ed.). : Felleisen's et al. treatise on systematic program design
- Operating Systems: Three Easy Pieces : Conceptual OS fundamentals: virtualization, concurrency, and persistence
- Immersive Math : World's first linear algebra book with interactive figures
- Mathematics for Computer Science : MIT course notes for discrete mathematics
- Guide to Discrete Mathematics : Part of the Texts in Computer Science book series
- Beej's Guide to C Programming : Beginner friendly practical guide to learn C
- Modern C : 2nd edition of Jens Gustedt's book on C17
- Structure and Interpretation of Computer Programs : Computer science text used in introductory courses at MIT
- Practical Common Lisp : Peter Seibel's Common Lisp book
- Starting Forth : Leo Brodie’s iconic introduction to the Forth language
- The Craft of Text Editing : A Cookbook for an Emacs by Craig A. Finseth
- Cryptography's Role in Securing the Information Society : National Academy of Sciences publication
- The Elements of Style : The classic reference book for writers by William Strunk, Jr.
Utilities
- OSDev.org : Community of operating system developers
- cheat.sh : Concise cheat sheets for command line programs
- Learn X in Y minutes : Community-driven language tutorial repository
- Shodan : The world's first search engine for Internet-connected devices
- Applied Cryptography Research: A Board : An applied cryptography research resource
- Build an 8-bit computer from scratch : A programmable 8-bit computer from scratch on breadboards
- Understanding statistics through interactive visualizations : Interactive visualizations for understanding important statistical concepts
Miscellany
- Epigrams in Programming : Collection of quotes from Alan Perlis
- Founders at Work : Collection of interviews with famous tech founders
- The Size of Space : Interactive scalar visualisation of space
- The Tail End : Visual representation of the human lifespan
- The Bitcoin White Paper Visualized : Graphic of Satoshi Nakamoto's whitepaper
- ForwardCom : Proposal for a forward compatible open instruction set architecture