This is an archive of a previous version of the ArcGIS REST API, formerly called the ArcGIS Server REST API.
We recommend that you use the current version instead. It is available at http://resources.arcgis.com/en/help/arcgis-rest-api/.
You will be redirected to the current version automatically or you can click on the 10.0 link below to access the archive.
If you really need to access the 9.3 materials, they are still available: