Those worried about the longevity of their tweets have another reason to relax. The Social Archive, which also stores status messages for many StatusNet-powered sites, is entering the Twitter search game. It joins Topsy, Tweet Scan and Twitter's own search engine, which received a recent upgrade.
The Social Archive API is still fairly new, but has search documentation to show its full search API, launching this week. The service will allow keyword searches of Twitter and other services with status messages. Additionally, you can restrict results by user, location, or service. The Social Archive claims 200 StatusNet sources, which includes Identica. Plans are in the works for Facebook status archival.
There are several other options for Twitter searching, starting with Twitter's own service. In August we reported about Twitter's short search history. Recent improvements doubled its search index, which means more tweets, according to a Twitter engineering post:
But you might wonder: Fine, it’s faster, and you guys can scale it longer, but will there be any benefits for the users? The answer is definitely yes! The first difference you might notice is the bigger index, which is now twice as long -- without making searches any slower. And, maybe most importantly, the new system is extremely versatile and extensible, which will allow us to build cool new features faster and better. Stay tuned!
That's good news, at least for finding results from the last week or so. But what about earlier tweets? The Topsy API, which we called Twitter search without an expiration, stores over 5 billion tweets across 500 servers and a petabyte of data. And then it makes all of this available for search, including its ranking algorithm that determines the quality of tweets.
If you're looking to search more than Twitter, there's another option. Like The Social Archive, the Tweet Scan API provides access to historical messages from both Twitter and StatusNet sites. In my tests, Tweet Scan isn't so good at the recent results, which seems fine since that's what Twitter can handle. Tweet Scan does go back at least several months, which means used in tandem with Twitter it could catch plenty of tweets.
In total, our API directory contains seven Twitter search APIs. Those not listed here are search services of a different variety, providing access to links, profile information and real-time web hook access to Twitter. If you're not just looking for search, there are 55 Twitter APIs in the directory, from data analysis to mutual follower calculators.