Here's a snip from John Markoff's NYT profile of David Ulevitch, the 25-year-old founder of OpenDNS.com. The service launched last year with a $2 million from ex-CNET-CEO Halsey Minor:

Mr. Ulevitch?s offer is quite simple. People who sign up for his service at OpenDNS.com are promised an easier way to locate Web pages and more protection from people who try to steal personal information from Web users. It can also block Web sites that offer pornography or other undesired material.

He does this by using the Domain Name System, or DNS, which is the phonebook for the Internet. Every Web site is assigned unique machine-readable numbers which are used to direct Internet traffic. Mr. Ulevitch inserts his service between a user?s computer and the broader Internet. When an Internet-connected computer or router is configured by adding OpenDNS.com?s two numbers ? 208.67.222.222 and 208.67.220.220 ? OpenDNS makes it possible to access Web sites faster.

His service will also correct standard spelling mistakes. For example, if a user types google.cm instead of google.com, OpenDNS will redirect the query to the correct Web page. OpenDNS also makes it possible for users to use the Web address query box of a Web browser in the same way users now use the search engine query box found in all modern Web browsers. Typing a search request into the regular Web address box on a computer that uses the OpenDNS service will return search results and related advertisements from Yahoo.

Image: Jim Wilson/The New York Times

Reader comment: Glenn Fleishman says,

I have a little bone to pick, but just a little one, with David Ulevitch. I have no complaints about what he's done with either DNS service, but John Markoff repeated David's contention that: "OpenDNS can also do a better job than an Internet service provider because its computers cache the most current address information."

This isn't inaccurate, but it's misleading. All ISPs and all DNS servers of any sensibility cache. What David apparently meant, however, is that ISPs and others don't intelligently cache information, leading to dumping or repeated retrievals of DNS data that could just have been kept on hand. That's certainly correct, but it's also something that could be solved through better DNS server software settings--something that there's no way to enforce externally by any party!

The secret to OpenDNS's quality, therefore, is due to their ability to control the intelligence of how they cache, and their ability to have the right number of servers to handle load. They may also replicate their cached data across servers, since it could be less expensive to synchronize their cached data than to query authoritative DNS server from each OpenDNS cluster around the world.

Since most ISPs don't care, they won't improve. Some ISPs even set their DNS servers to query too often or too seldom compared to the authoritative information provided in a DNS record.