Twitpic allowed you to share photos on Twitter long before you were natively allowed to do so from within Twitter.
The company cites a trademark dispute with Twitter as the reason it's shutting its doors.
In a blog post, Twitpic founder Noah Everett writes that Twitter threatened to cut off access to its developer tools:
A few weeks ago Twitter contacted our legal demanding that we abandon our trademark application or risk losing access to their API. This came as a shock to us since Twitpic has been around since early 2008, and our trademark application has been in the USPTO since 2009.
Rather than fight the company, the post reads, Everett decided to shut Twitpic down. That means that all the old tweets that include Twitpic pictures will have dead links.
And that includes animated GIFs. Twitpic is currently one of the only ways to tweet out the file format on popular Twitter feed readers like TweetDeck.
Twitpic will offer a way to download photos and videos that remain on the site within the next few days.