Technically, you don't need ArcGIS installed to develop or deploy ArcSDE applications
(either Java or 'C' API). In practice, it's useful for developers to have access to the
ArcSDE administration binaries ('sdelayer', 'sdetable', etc) in an ArcSDE for {DBMS}
installation, but once the application is compiled, then you only need one ArcSDE
client install (which includes ArcGIS Desktop and Server, the SDK, and all ArcSDE
server installations).
- V