Not exactly a gap. It's just trying to be a domain-specific site. There're plenty of examples of this. For example, you could view HN as a domain-specific digg or reddit, for tech/startups. Even though you can make a subreddit or similar.
Perhaps they felt there was a lot of bad quality for HTML/CSS question and answers on StackOverflow, so they built this. I don't think so, but it's possible that the creators do.
I think there are a lot of poor HTML/CSS questions and answers on Stack Overflow, but I don't think separating them other programming questions and from non-front-end programmers is really going to help anyone.
Well, for one you don't need Openid to register. Stack overflow scares a lot of potential users. It is more geared towards programmers as opposed to designers.
Screw it. I've implemented it many times and still don't prefer it myself. I like to be able to setup a new separate semi-anonymous account on each site I use.
I too am not a huge fan of current implementation of OpenID. However, if you have a throwaway account on Yahoo or Google, it is trivially easy to signup on Stackoverflow.
You can't prepare yourself for all the sizes and shapes created by the user. The minute you give up control of content you will end up with crap that like. If he had used tables at least the layout would have adjusted accordingly. It would not have looked pretty, but it would've been usable.
Also a much more focused user base. From an advertising point of view, do you think it's easier to sell 10,000 uniques on a general web technology site or 5,000 uniques on a site that has a very specific audience like web designers?
I would argue that the SO userbase is already highly focused - on developers. Its not "general technology site", just "general developers" site. Its not as if that's an especially large and poorly defined group.
With a much smaller subset of potential users I think you'll also find a much more "focused" group of advertisers, i.e. a smaller group of interested advertisers.
I can see them sharing the same database for both sites but displaying the CSS/HTML questions both on doctype and SO, but doctype restricted to CSS/HTML only. This will allow them to get content through multiple channels but allow them to sell more targeted ads on doctype.
Since SO content is licensed under creative commons, there's no reason they can't feed in all questions into SO... I suppose it might be tricky to merge votes of the (much larger) SO audience with votes of their audience, and has interesting implications to SO's business, but it's certainly doable.
One point: people here seem to be assuming they want to sell the ad space on the right hand side of the page.
Rather, I suspect that the whole site is an advertisement for their services. If they're successful, they'll gather huge amounts of google juice (for good reason, with useful links).
Further, I suggest that people should view this as good, organic marketing, rather than as some sort of evil practice because their intent is to market. There should be lots more marketing like this.
I've become convinced that CSS is an elaborate trick played upon graphics designers; It's an impressively inappropriate tool for laying out text, but given a few hundred hours of trial and error, you can make anything almost work.
I think it's telling that no UI toolkit uses anything that remotely resembles the HTML box model.
These sites are 90% SEO focused (even if they don't admit that it's true). I wonder if it's better to separate it all out on these different sites. They have to build up PageRank on each one separately. It seems risky, although it probably will benefit them in the long run because they'll effectively compete with themselves.
What would validation prove? These guys created a website so you can talk to experts on web design. They are not claiming to be experts on that topic themselves. Even if validation meant much it would seem unfair to hold the owners of this site responsible.
If they actually served the pages with the correct Content-Type, their pages would not render in any browser.
You mean it wouldn't render in IE. In any more reasonable browser, if there were any parsing errors in the XHTML then you would get a big fat error message but otherwise it would render just fine.
I could have been a bit more specific in my earlier comment as I include Firefox in the group of reasonable browsers, even though with it, you get the YSOD. I know a lot of people swear by Opera, but I don't use it, so won't include it in my reasonable browsers list purely for subjective reasons.
Though as I said, what does it matter now that XHTML 2 has been canned.
Of the three pages of questions currently on the site, none of them would be better described as "design" than "frontend development."
It's time we granted these separate professions the dignity of their own names instead of forcing everything into the hodgepodge of "design."