<p>A free, community-maintained wiki archive hosted by Art of Problem Solving, curating links, past problems, and theory articles for mathematics olympiads worldwide. Covers national competitions such as AMC, AIME, USAMO, and IMO as well as many regional olympiads, with cross-referenced problem databases and worked solutions. A widely used supplement for students preparing for SMO, AMC, AIME, and higher-level contests.</p><ul><li>Coverage includes AMC, AIME, USAMO, IMO, and many national and regional olympiads around the world</li><li>Problem databases, worked solutions, and theory articles on number theory, combinatorics, geometry, algebra, and inequalities</li><li>Entirely free; no account or signup required to browse</li><li>Self-paced: useful for casual problem practice or structured olympiad preparation</li><li>Cross-linked to the wider AoPS community forums and the AoPS online school</li></ul><p>Browse the archive directly at the URL; creating a free AoPS account is optional and enables participation on the community forums.</p>