ActiveDen was an Envato Marketplace that specialised in Flash assets.
Beginning in August 2006, ActiveDen was the first building block of the Envato creative ecosystem and its success paved the way for the marketplaces and products that followed.
By 2015, the market had moved away from Flash, for a number of reasons (including HTML5) and after lots of thinking and consideration, Envato decided it was time to say farewell. ActiveDen's last day of operation was February 29, 2016.
If you would like to read more about ActiveDen please read this article (The Rise and Fall of a Multimillion Dollar Flash Marketplace in One Chart)
Read the blog post announcing the closure here.