Unfortunately, if you don't speak Russian, it will be hard to figure out what they do :) They extract structured data from Wikipedia and other sites (e.g. shopping sites, music sites, etc) and aim to give you an "instant answer" as you type, or on top of the results page.

Here is an example where they solve a quadratic equation for you:

Here is an example where they solve an inorganic chemical reaction:

And now an even more complex chain reaction:

Super smart search suggestions as you type are where Nigma excells: they give you the direct answer as you type, if possible. The screenshot below says "capital of b" and the dropdown suggest meny says "capital of brazil ANSWER: Brasilia", "capital of bashkiria ANSWER: Ufa," "capital of bulgaria: ANSWER: Sofia" etc. Naturally, you can directly click on the links and learn more about Sofia and Brasilia without having to stop at the intermediate search result page.

If you type the query "apple inc", you will see the drop-down below. It tells you that Apple is a public company, its revenues for the last year, notable people (Steve Jobs and Wozniak), etc. Pretty cool.

Another cool feature is price comparison right in the suggest box. (BTW, comparison shopping engines seem to be popular in Russia to begin with.) Here, the user types "note" as in notebook computer, or laptop, and the menu shows prices for popular laptops, with min, max, and average prices:

You can also look up restaurants, and receive structured and well annotated results back, similar to Yahoo's Search Monkey, like in this example for "Sup Cafe phone number":

Music search is very impressive too. Here is an example of a result for "modern talking":

You see what Google calls OneBox, and Yahoo calls Wow module: a large direct result on top of the page, which combines photos, album information, play button, lyrics, and even a link to directly download the songs (which in Russia, being a free country unencumbered by copyright issues and RIAA, is free):

Pretty cool, huh? Of the major search engines, Yahoo! leads in music search, but Nigma may have leapfrogged everyone here. Nigma also has a similar and pretty awesome book search, which finds all sorts of metadata and links to an electronic version of the book or an online bookstore to buy a paper copy. Russians are avid readers, and Nigma has made a great product for them.

Nigma claims that they are working with Hector Garcia Molina from Stanford. It is a verified fact that they keep adding new and cooler features just about every week! Everything they do is built upon structured data.

Unfortunately, Nigma's current product is almost entirely in Russian. They are a company to watch! Given how much more structured data there is in English, I would not be surprised to hear more about them soon in the US as well.