Wikisource is an online digital library of free-content textual sources on a wiki, operated by the Wikimedia Foundation. Wikisource is the name of the project as a whole and the name for each instance of that project ; multiple Wikisources make up the overall project of Wikisource. The project's aim is to host all forms of free text, in many languages, and translations. Originally conceived as an archive to store useful or important historical texts, it has expanded to become a general-content library. The project officially began on November 24, 2003, under the name Project Sourceberg, a play on Project Gutenberg. The name Wikisource was adopted later that year and it received its own domain name.

The Wikimedia Foundation, Inc., abbreviated WMF, is an American 501(c)(3) nonprofit organization headquartered in San Francisco, California, and registered there as a charitable foundation. It is the host of Wikipedia, the seventh most visited website in the world. In addition, the foundation hosts 14 other related content projects. It supports the development of MediaWiki, the wiki software that underpins them all.