How does one programmatically find newly available domains?

Question

There are online tools (i.e. http://www.swola.com/) for discovering newly available domains.

Given a corpus of domain names, it is easy to periodically check their records and raise a flag when one becomes available. However, checking periodically the records for all registered domain names in the world sounds excessive/impractical.

What is an efficient way to programmatically discover such domains? How such tools work?

Answer 1

I don't have enough experience with the data to determine how up to date it is (for example if someone renews a domain a week before it expires, how quickly is it removed from the list?) but I discovered that pool.com has a database of upcoming domains sorted by expiration date. It's a relatively simple matter to create a cron job that downloads this file, parses it for the specific domains you want (for example, domains that expire tomorrow, domains with only characters a-z, domains up to 9 characters, domains with KEYWORD in them, .coms, etc) and emails you a daily report.

One thing that I would like to hear about is how others are ordering these domains as soon as they become available. I know some registrars offer that service but usually at a great expense.

Here's my script, I threw it together in a half an hour but hopefully it will be useful to you.