I often search for Cocoa Touch and Cocoa class names to get at Apple's reference docs. XCode has them available offline, but this actually takes much longer than googling, and the doc viewer doesn't seem to support tabs.

DDG does fine for some of these (e.g. UIView), while some don't even list in the top 20-30 (e.g. UITableViewController). Google isn't 100% reliable for this either (Apple recently changed their URLs which probably cost them PageRank juice) but it's near enough. DDG is unusable for this specific pattern. I don't know if fixing it would adversely affect other searches, though.

A "!" bang syntax would be fine by me, if that helps. (that's option-shift-K on QWERTY I think)

One thing that would really help and guarantee that I use DDG over Google for this kind of search would be to keep your links to documentation pages up to date, or at least give an easy selection.

Google is really bad at this. For instance, most links to pages in the Apache docs on Google are for 1.x, which all have a big header that says "This is deprecated, use 2.x". I use 2.x so the 1.x links are annoying, and it would be difficult if Apache didn't provide a link right there.

Another example is PostgreSQL. Google has _always_ been bad at providing up-to-date links to the PgSQL manual, even now it's usually 8.0-8.2 results that come up (the current version is 9.0.x). It's annoying because Postgres doesn't have an easy jump-to-current link like Apache, so I have to go up to the address bar, delete the older version number, and replace it with my current version number or the word "current", which always points to the latest.

I know it would be hard to do this for general results, but for official documentation it shouldn't be too difficult since the URLs usually contain the version number in a reliable format.

So, if I searched for "postgresql grant", as an example, I would like recent results to come up, or at least an easy way to choose which version of the documentation to use before I clicked out. If I have to write "postgresql grant 9.0" or something similar that would be OK too. Google does poorly at this even when you specify the version number you want as just shown.

Specifically I generally search error strings, and expect to get relevant links to archived mailing lists.

Gotcha. I would love to do more with 0-click there. Does anyone know of any good/great listings or search engines for error strings?

I occasionally use http://www.errorhelp.com/ - it's a database of error messages and (hopefully) their fixes.

I switched back to Google because it performs significantly better on technical mathematics searches, which is mostly what I look for. On computer programming searches DDG and Google seem to do about equally well. On some domains I wouldn't be surprised if DDG does better.

To add on to this, every search engine is generally pretty bad at math related searches. It may be something worth looking into.

Can you give some examples as to math searches, the more the better :)

There are two major problems I've found.

1. Poor interpretation: "distribution of compact support" brings up nothing very useful in DDG -- a bunch of linkfarms, it looks like -- but in Google the third result for me is a relevant .pdf from Oregon State.

2. Users attempting to ad-hoc convert math notation into ascii: Google understands "l 2 space", but DDG thinks I mean "l2space" which is some sort of gallery in I don't know where.

It's a hard, nontrivial problem.

I think this actually homes in on one of the bigger issues with setting up a competing search engine, you have to be equal to or better than the incumbent all the time, and that is really hard.

The use of familiar everyday terms for technical mathematical objects makes this difficult ("net", "space", "compact", etc.). Since most pages are either all about math or have nothing to do with math, I wonder if there's an easy way to tag the former pages, which would then be used as an advanced filter available when searching. ("Is this a math search?")

I find that DDG is great for finding most of the programming-related stuff I'm looking for, but if I need to find more recent information, it's starting to fall behind.

For example, a recent AVG update caused widespread boot failures on 64bit versions of Windows 7. Searching "avg windows 7 crash" in DDG (and some other variations) is not returning very high-quality results at the moment; the top couple of results are from much older issues, the next one is a couple of paragraphs from some site about AVG apologizing for the trouble, and so on. Google isn't a lot better, but at least its top result is a brief article from Computer Weekly on the issue.