Twitter has announced that they are killing support for Microsoft's Internet Explorer 6 and Internet Explorer 7 starting May 13th. Twitter's Tweet button was first introduced in 2010 and was built around Internet Explorer 6.
"When the Tweet button was introduced in 2010, Microsoft’s Internet Explorer 6 was our baseline. Now, most users have upgraded and we see IE6 usage dwindled. On May 13th 2013, we’re going to prune our support for that browser and its successor, IE7," Twitter stated in an official blog post.
In essence, the Tweet button, Follow button, embedded Tweets, and Twitter timelines will no longer work in Internet Explorer 6. "The script will detect the unsupported browser and silently exit. The content from the embed codes will remain in place," Twitter adds. The framework that allows developers to respond to user interactions with Twitter widgets will no longer work in IE6 and IE7.
In Internet Explorer 7, however, widgets will still be rendered but only for the time being as the browser is now given "limited support" and future features may not be implemented. Although support for IE6 and IE7 is dead, “Tweet” links will still share your page, “Follow” links will still point to a users’ profiles, and embeddable timeline codes will link to the main timeline on the Twitter website.
Again, this does not take affect until May 13th.