Uniono por la Linguo Internaciona Ido (ULI), the Union for the International Language Ido, is the official union of the Ido-language movement. Based in Amsterdam, the Netherlands, its main functions are the propagation of the language, arranging the yearly conferences in which Ido speakers gather, and the publishing of the magazine Progreso (progress), begun in 1908 by Louis Couturat, one of the founders of the movement who died in 1914. Currently there are representatives from 23 countries as official members of the union.
The 2008 conference was held in Wuppertal, Germany, from 22 to 26 August.