The technical articles, API reference material, and sample code you need to develop against the ArcGIS 9.3 platform are now located within the ArcGIS Resource Centers.
The links below point you to specific places within the Resource Centers where this content now resides.
Don't forget to update your bookmarks to point to the new location!
The ArcGIS Desktop Resource Center houses the following developer resources that previously existed here on EDN.
If you are building custom, lightweight, desktop applications that utilize ArcGIS Engine Runtime, then the ArcGIS Engine Resource Center houses developer resources that previously existed here on EDN. By development language, these are:
The ArcGIS Server Resource Center houses the following developer resources that previously existed here on EDN.
If you create tasks that utilize GIS services, geographic content, and other Web services in ArcGIS Explorer, the free desktop client to ArcGIS Server, its developer content for Build 500 is here.
If you are creating in-the-field applications using the ArcGIS Mobile SDK, technical articles, API Reference, a blog, and other resources are available in the ArcGIS Mobile Resource Center.