The MusicBrainz C Library by MusicBrainz is a client library to assist developers in creating MusicBrainz disc IDs and freedbs from audio CDs. The MusicBrainz database contains a huge amount of music metadata, which is maintained by the MusicBrainz community.
Blekko is a search engine which uses both algorithms and human interaction for producing high quality search results. Currently serving more than 3 billion pages, Blekko sorts through spam, content farms, and sites containing malware in order to offer only real information to the end-user.
With Twitter reducing its search history to four days, it is a challenge for applications that are dependent on search results, that went not days but even months back. Several applications have taken on the challenge to fill this void and are building search indexes on top of Twitter. Topsy is one of them and it's sharing its results as an API.
Google has announced the launch of a new Indexing API that publishers can use to notify Google when job posting pages on their sites have been updated. According to Google, the use of the API "allows Google to schedule job postings for a fresh crawl, which can lead to higher quality user traffic."