Australian Open | French Open | Lucille Ball | Open University | open source | U.S. Open | Dragon Ball | Wacken Open Air | The Open Championship | Headbangers Ball | Dragon Ball Z | U.S. Open (tennis) | All England Open Badminton Championships | U.S. Open (golf) | Open Source | Open-pit mining | 2006 Australian Open | Open Software Foundation | Indira Gandhi National Open University | Great American Ball Park | Ball State University | Lamar Hunt U.S. Open Cup | ball | Alan Ball | 2005 Australian Open – Men's Singles | U.S. Women's Open | open access | Hugo Ball | Gerry Weber Open | Ernie Ball |
Examples of topologies include the Zariski topology in algebraic geometry that reflects the algebraic nature of varieties, and the topology on a differential manifold in differential topology where each point within the space is contained in an open set that is homeomorphic to an open ball in a finite-dimensional Euclidean space.