Web Based EM DB Control for Oracle 9i

There is no actually web version EM database control for oracle 9i. But DBAs can launch EM from web browser through JInitiator.
Oracle JInitiator is implemented as a plug-in (Netscape Navigator) or ActiveX Object (IE).
Oracle JInitiator allows you to specify the use of the Oracle certified JVM (Java Virtual Machine) on web clients instead of relying on the default JVM provided by the browser.
There are many docs on OTN website.

Some versions of JInitiator (ex. 1.1.8.19) must be plugged in manually to Firefox. These are the steps:
1) Install JInitiator.
2) C:\Program Files\Oracle\JInitiator 1.1.8.19\bin\NP JinitXXXX.dll XXXX = version
3) Paste it under this directory of Firefox (C:\Program Files\Mozilla Firefox\plugins)
4) Restart Firefox.