Which Wikipedia sister project is a free library of source texts?

The Wikipedia sister project that serves as a free library of source texts is Wikisource. It hosts public-domain and freely licensed works such as books, speeches, legal documents, historical records, and other previously published texts.

Wikisource is different from Wikipedia because its main purpose is preservation and transcription rather than the creation of encyclopedia articles. Volunteers may scan, proofread, format, and organize source documents so that readers can search and read them online. Many works are presented alongside page images, allowing users to compare a transcription with the original document.

The project was added to the Wikimedia family in November 2003, initially under the name Project Sourceberg, a playful reference to Project Gutenberg. It was renamed Wikisource in December 2003. The name reflects its role as a source-text library. Wikidata stores structured data, Wikivoyage provides travel guides, and Wikinews publishes news reports; none of those projects is the Wikimedia free library devoted primarily to original source texts.