Flickr

The service emerged out of tools originally created for Ludicorp's Game Neverending, a web-based massively multiplayer online (MMO).

Founded by Stewart Butterfield and Caterina Fake.

What is Flickr?

 * Flickr is an image hosting and video hosting website, and web services suite that was created by Ludicorp in 2004 and acquired by Yahoo! in 2005.
 * In addition to being a popular website for users to share and embed personal photographs, and effectively an online community, the service is widely used by photo researchers and by bloggers to host images that they embed in blogs and social media.

Accounts

 * Flickr asks photo submitters to organize images using tags (a form of metadata), which enable searchers to find images related to particular topics, such as place names or subject matter.
 * Flickr offers three types of accounts: Free, Ad Free and Doublr.
 * The free option includes one terabyte of storage limited to 200 MB per photo and 1 Gb per video. The Ad Free option allows subscribers to avoid advertisments for an annual fee.
 * As the name suggests, the Doublr account includes two terabytes of storage. 514px-Flickr_wordmark_svg.png