There are quite a few developers like him. Sure, he's one of the first and most famous, but having worked in the game development space for a while, I can safely say that there are people quietly writing equally, if not more impressive graphics engines.
He wrote the first side-scrolling engine for PCs (long before they were called that) back when it was considered impossible.
He made people sit up and take notice of Shareware
He wrote the engines for Commander Keen (2d platformer) Wolfenstein (3d) , Doom (3d with variable height floors/walls), Quake (full 3d), Quake II (coloured lighting etc) etc etc
He's one of a very small number of people who were writing groundbreaking code right at the beginning, and are still writing groundbreaking stuff.
He's constantly made his code public, as much as possible
He loves fast cars; how does a 1000hp twin turbo w/24psi of boost Testarossa sound? (that was 11 years ago)
He founded a company that builds and flys some serious rockets. real ones.
Seriously, if that doesn't make you a coding god, what does?
id Tech 5 is going to introduce the entire concept of megatexturing - the grand unifying theory of geometry, just as Doom 3 was the first major engine to implement a unified lighting model. This is going to have major implications for both content production and rendering, and is exciting as fuck.
Carmack's impressiveness is not only in his ability to write kickass looking engines, but also his ability to lead the pack in completely rethinking the sort of things most devs take for granted.
He uses the name "Sparse Virtual Textures" instead of megatextures so it's not very googleable. Also it's a video, not a paper, but the code is included.
What I meant to say was that there are many great engineers who are quietly developing fun and technically impressive games.
Also, I had some deja vu and Googled up a comment I wrote a while back. It is about why I feel that Carmack has missed the mark on several major game technology trends: http://news.ycombinator.com/item?id=419606
It's not just ability and skill, it's also impact on the industry (which, obviously, requires a degree of luck and circumstance). It sounds pretty hash, but it's kinds hard to be considered a legend/god/whatever if no one's heard of you.
But you raise an interesting point. For those people how do make an impact, to what degree is it due to circumstance, and to what degree their own skill? There's loads of very highly skilled people in any given field, and yet only a very small number of them will ever make much of an impact on that field. Why is this, and what differentiates the ones who do from the ones who don't?
That's why I left Reddit—the tyranny of the majority. I guess it's here now, too. Where to next?
Here's a parable: imagine that you and your friends are all playing a pen-and-paper RPG with a focus on storytelling, getting along, quite happy to collectively have interesting things happen to all the characters. Then, imagine that a new guy joins, and he's a munchkin—he plays the game to win, getting all the other players angry. He doesn't like his character to "get screwed" to tell a good story, and so on. The other players realize this, but they put up with it, hoping, for a while, that he'll eventually adapt. But he doesn't. So, eventually, the other players begin to leave—and new players join that play in much the same way the munchkin does. Eventually, the group is no longer story-focused, but is rather completely focused on collecting imaginary points and tokens.
See what I mean? Although karma doesn't matter objectively, if it's important within the "shared delusion" of the majority, it can still do damage. That something was voted high or low wasn't the basis for my statement—it was that it seems, lately, that the majority shares the delusion; that this place is a munchkin group.
witch brings us to the point: You are right and the majority is wrong. But without good explanation, you still deeply care about what other people think about you("it still can do damage").
When I played pen-and-paper RPG, the storyteller used to favor her friends-interest over anyone else(the majority), so maybe that is the real objective: Impose your way of thinking over the majority, If not, you don't play.
That's not quite what I meant by the phrase. It "does damage" because others in the majority accept that it does—for the same reasons that I am "in debt" when a number on a machine reads negative. I might agree or disagree with the conception of money as a fiscal instrument, but it is supported by the group in a way that prevents me from participating in the group unless I acknowledge it and treat it the same way that they do. To not acknowledge money (or karma) is, in effect, an act of self-alienation. You "reject yourself" from the group by doing it, because the game they are now playing is a competitive one—and if you do not acknowledge the table stakes, you cannot ante.
This is why it is important to do some research on social game design (or consult a game designer) before you code a game mechanic into your social webapp. Years of research into MUDs and MMOs show that different mechanics reward, and thus encourage, different types of player-styles, and thus shift the user-base in different directions.
Here's the most famous paper on the subject, just to get anyone interested started: http://www.mud.co.uk/richard/hcds.htm . It would be awesome if someone would write an "Interpreting Bartle for Web 2.0" article and submit it back here; I've been meaning to do it for months now but it's still a ways down on my to-do list.
The credit roll at the end of high-end games is filled with level designers, artists, qa, management, designers, etc. The actually developer section is relatively small.
Also, not many other graphic engine programmers have their own company. They might be as good or better as Carmack, but they are hidden under layers of corporate obscurity. The guys at Crytek who invented SSAO come to mind - most of the time SSAO is credited to Crytek and not to individual people (which is a shame, imho).
( SSAO: http://en.wikipedia.org/wiki/Screen_Space_Ambient_Occlusion )
The best way I can rate someones skills is by reading his code. Just seeing the result makes it much harder to evaluate how intelligently it was written. Small exceptions are graphic engines which can do stuff which was never possible before in such a radical new way -- Carmack also did this a few times but in most cases, the code was also released a few years later. (Only exception I know was Commander Keen. But it was obvious that he introduced something very clever and new here. And it was also not unknown how he did it after those games were released.)
JC was doing this stuff back before you could Google how to do it, or buy a book at your local B&N telling you how to do it. That counts for a lot. So does his consistent willingness to bring the fire down the mountain and hand it to the masses.
Additionally, post Quake 3, the team at Epic routinely chose better design tradeoffs for real world games. This includes both performance tradeoffs and spending of engineering effort on production needs (like a solid level editor). Hence the popularity of the Unreal 3 engine.