Tumblr
Tumblr is a site that allows for photo or art blogs. In practice, it's somewhat similar to Livejournal and DeviantArt, and wouldn't really warrant any interest from the *chans or /tg/ in general if it weren't for the fact that there's a number of artists on tumblr catering to some of /tg/'s many interests, and its often stormy relationship with 4chan for reasons too complex to describe within the scope of this article.
What is Tumblr?
Tumblr is a microblogging platform owned and operated by Yahoo! Incorporated. The service allows users to post multimedia and other content to a short-form blog. Users can follow other users' blogs, as well as make their blogs private, if desired. Much of the website's features are accessed from the "dashboard" interface, where the option to post content and posts of followed blogs appear. This enables, in theory, a stream of content even if a given blogger is not able to actively update that often. In practice, Tumblr's ability to reblog individual blogs tends to lead to a lot of flat-out cropped content from other blogs, but that's not what brought it to /tg/'s notice.
To make a long story short, idiots from the site tried to raid 4chan and failed miserably- several times in a row. The less you know about the details, the better.
Art Blogs and Shit /tg/ Actually Cares About
tg weavers trash heap: monster girls, you love them, I love them, we love them
To Be Filled In.