"The Metadata Analysis and Mining Application" (MAMA) engine is a search engine that works in a really different way. It indexes based on page structure: markup style, scripting, coding,...
"Say you want to find a sampling of Web pages that have more than 100 hyperlinks or for pages that use the Font-size CSS property that also use the FONT element with a Size attribute? Many parties would be interested in such a service, even if the market would be smaller than for a "traditional" search engine."
They also say:
- Browser manufacturers and others can use MAMA data on the popularity of widely used technologies to prioritize bugs and justify adding support for new technology to in-progress releases.
- Standards bodies can use the data to measure the success and adoption rates of various technologies.
- Web developers can use the same data to justify support of various technologies in their work.
- It can provide real-world, practical samples of the Web developer's "art", for inspiration and instruction.
You can get a load of interesting facts from it like, what the most popular element on the internet is, or how popular Fash is,...there's a key findings report you can have a look at. It has a load of stats on things like which server is the most popular, how many URLs in the index passed validation, the average length of external CSS and so much more.
You'll also find interesting the document "The "average" web page", all about how those look today from a structural perspective.
It's a dream come true for developers, and I think that it'll be quite popular.