From OpenStreetMap Wiki
Perhaps you were looking for...
- Editing - A list of many different editing software options for OpenStreetMap
Or perhaps you were looking for software called "Osmeditor":
- Osmeditor (QT) - Desktop app written with QT. No longer maintained and has been non-functional since 2007. This is the original "Osmeditor" (page moved from here) We can forgive them for the unimaginative name since this was one of the earliest OpenStreetMap Editors to be developed.
- ArcGIS#ArcGIS Editor for OSM - And ArcGIS plugin and also a (totally separate) iPhone app. ESRI folks will refer to either or both of these things as the "osm editor".