In late 2008 and early 2009, users submitting their work to Hacker News began prefixing submission titles with "Show HN". This caught on , and "Show HN" became a sort of badge for posts sharing original work with the community. Show HN threads became places for in-depth discussion of new work. They are a way for products to get users, creators to get feedback, and readers to learn and be inspired.
There have been about 24,000 Show HNs so far. The first used the title "Show and Tell HN", and was GitHub-related. The second, and the first to use the "Show HN" convention , was a face recognition project. And the third was a Hacker News alternative. Plus ça change...
Hacker News users have grown fond of their Show HNs. We often hear that they're the best part of the site. We hope there will be many more, and look forward to seeing what you all come up with!
 But it took a while: there was 1 post in 2008, 9 in 2009, and 452 in 2010.
 Its submitter, lbrandy, says the title "was definitely a play on 'Ask HN'."