Distributed Proofreaders, a volunteer group founded in October 2000, checks scanned public-domain books one page at a time so they can be published free on Project Gutenberg. In December 2025 it completed its 50,000th title, A Dictionary of the Art of Printing, written in 1840 by the printer William Savage as an update to a printing manual from the 1680s. The dictionary explains printing and binding methods, the slang of the trade and the fonts of British type foundries. A volunteer who goes by jandac prepared the final edition, and the group marked its 25th year with special anniversary projects.