The Steam Workshop is a content-hosting service provided to developers, with the purpose of hosting player-created content specific to software. Content on the Workshop is software-specific, meaning content created for one game cannot be used in another, and is integrated by utilizing Steamworks, although not all software has Workshop functionality. Developers are able to choose what players may upload to the Workshop for their software.
The Steam Workshop was originally designed for use with Team Fortress 2; however, Valve later designed it to have integration functionality with any software, as long as the developer allowed it. Games such as Portal 2 and The Elder Scrolls V: Skyrim utilize the Workshop for map-creation and modifications, respectively. Dota 2 became the third Valve-published title that utilizes the Workshop in June of 2012, featuring customizable accessories and character skins.
In January 2015, Valve had paid $57 million to certain content creators to develop content for Valve-published games such as Team Fortress 2 and Dota 2. In this month, Valve also began rolling out features to allow developers access to the Workshop and went live in April 2015. It was removed a few days afterwards, following copyright misuse and pricing reports. It was re-added November 2015, with fixes to the Workshop to prevent the previously mentioned issues from recurring.