HOSI Wien — Homosexuelle Initiative Wien — A principal iniciativa pela igualdade LGBTQ+ em Viena.

HOSI Wien — Homosexuelle Initiative Wien — was founded on 27 January 1979 as Austria's first political gay-rights organisation. Its founding purpose was the repeal of §209 of the Austrian criminal code, which set the age of consent for homosexual acts at 18 (versus 14 for heterosexual acts). It took HOSI Wien 23 years of continuous political campaigning to secure that repeal, in 2002; Austria then took another 17 years to reach marriage equality in 2019, which HOSI Wien also drafted the legislative case for. HOSI Wien is now the largest LGBTQ+ political organisation in Austria, with roughly 700 members and eight paid staff. Its scope has widened well beyond original age-of-consent advocacy: HIV/AIDS advocacy (from 1983 onwards, in partnership with the Austrian AIDS Life foundation), trans rights, refugee support, and the annual Vienna Pride organisation. Since 2009 HOSI Wien has occupied purpose-fitted offices at Heumühlgasse 14 in the 4th District — a converted commercial building holding meeting rooms, an archive of Austrian LGBTQ+ political records, a small library, and the HOSI-run Aufschlag magazine editorial desk. The organisation runs monthly member events and quarterly public programming. Office hours Monday-Thursday 09:00-17:00; visitors welcome for a walk-through and the ground-floor archive display. Karlsplatz U-Bahn is a five-minute walk. The organisation's history is preserved primarily in its own archive (accessible by researcher appointment) and in the QWIEN — Zentrum für queere Geschichte Wien archive at Neubaugasse.