If you don’t know of John Carmack, he is the guy who single-handedly wrote the engine for the initial Doom games: https://en.wikipedia.org/wiki/Doom_(series)
Do you have your own list of legendary “one-man army” programmers?
Surprised nobody has mentioned Addy Osmani. https://addyosmani.com/
Steve Wozniak, why didn't anyone mention him, he created the desktop computer.
Also John Draper and Aaron Schwartz
Myself, lol - though I'm neither famous nor legendary (I don't think so anyways)
5 years in, 3 versions, the full stack of my startup has been developed, maintained and iterated by me and me alone. There's nothing I haven't been able to figure out how to build or couldn't. Being the only developer has been tough for sure; but sometimes you need to give credit where credit is due - yourself.
My favorite programmers (not necessarily in order of preference as all of them are legends)
Dennis MacAlistair Ritchie & Brian Kernighan - Creators of C & Unix still working efficiently in one form or another on wide range of devices in the form of Linux
James Gosling father of Java and wrote a version emacs called gosmacs. Go figure. Still developing and writes a blog at http://nighthacks.com/jag
Bill Joy - one of the founder of Sun Micro Systems and early hacker on BSD Unix - https://en.wikipedia.org/wiki/Bill_Joy
Linus Torvalds - Creator of Linux Kernel - https://plus.google.com/+LinusTorvalds/
Richard Stallman - GNU founder - https://www.stallman.org/
Eric S Raymond - http://www.catb.org/~esr
Brian Behlendorf - one of the creators of Apache
Paul Graham - http://www.paulgraham.com/index.html - Author of Hackers and Painters and one of the people behind Hacker News and https://www.ycombinator.com/
Joel Spolsky - Guy who wrote the early spec for Microsoft Excel one of the most successful business application for decades and built and building wonderful products still - Trello and StackExchange are few to mention. More details at http://joelonsoftware.com/
Google’s Jeff Dean - slate.com/articles/technology/doers/2013/01/jeff_…
James Gosling father of Java and wrote a version emacs called gosmacs. Go figure. Still developing and writes a blog at http://nighthacks.com/jag
One man comes to mind, I'm intimidated even typing his name: Fabrice Bellard.
He built his own 4G basestation which ran on a PC. He created ffmpeg. He wrote a linux emulator in Javascript. He created his own image format (BPG). These are the tip of the iceberg.
How one man is capable of achieving so much is quite astounding. Here's a quote from the article above:
"If there’s a secret to this superhero-level productivity, it appears to have less to do with comic-book mutation and radioactivity, and far more with discipline, confidence, rigor, and many years of practice."
John Carmack - the guy behind the DOOM engine, Wolfenstein, Quake games, Commander Keen etc. If you are interested in this topic, Masters of Doom: How Two Guys Created an Empire and Transformed Pop Culture is a great read of what he and John Romero did.
Donald Knuth - alone wrote the TeX system back in the 1978. Also wrote the book The art of Computer Programming.
Bill Joy - wrote vi, csh, rlogin, rsh, and rcp.
Ben Buchanan (200ok)
I make some bits of the web.
Hmm. I don't know that these will fit what you're thinking of, but legendary programmers and engineers....
Doug Engelbart. https://en.wikipedia.org/wiki/Douglas_Engelbart
Margaret Hamilton. en.wikipedia.org/wiki/Margaret_Hamilton_(scientist)
Grace Hopper. https://en.wikipedia.org/wiki/Grace_Hopper
Ken Thompson. https://en.wikipedia.org/wiki/Ken_Thompson
Dennis Ritchie. https://en.wikipedia.org/wiki/Dennis_Ritchie