BooRah, a semantic vertical search engine founded by former MetroFi employees, has indexed 100,000 blogs and over 100 review sites to create a nice restaurant review and search service for a variety of U.S. cities. Today, the Mountain View, Calif., company launched a partnership with online reservation agent BookingAngel that will allow folks to make online reservations with any California restaurant through the BooRah site.

There’s a lot to like about this startup — namely that it already has revenue from signing ad partnerships with 20 local newspapers — but also because Co-founder and CTO Nagaraju Bandaru wants to give back to the community.

He’s not talking about building houses in New Orleans, though. He’s giving back to the technical community through open sourcing some of BooRah’s entity mapping code, which analyzes semantic relationships on web sites and determines what type of business operates that site. As he explains, “We do a lot of stuff on MySQL that before would have cost us millions in Oracle databases, and $50,000 a year in fees, but we can now start a company for much less.”

So in a few months he plans to open source that code for other startups to use. Other than making me feel all warm and fuzzy about entrepreneurs sticking together, such efforts will only hasten technological innovation for end users. Even if BooRah doesn’t make it (although, given Bandaru’s efforts so far to get both advertisers on board and provide a premium service for restaurateurs, I think it has a good chance), its technology could enable another startup to quickly get up and running with a different use for that code.