Look at you...you've finally got red5 built from source. Now you're getting greedy and want to try developing for it.

Indeed, building at the command line has a nice nerd-factor, but building within Eclipse is wayyyy more practical for plugin development.

We're going to add some plugins to Eclipse:

1) Open up Eclipse
2) Go to Help > Software Updates > Find & Install
3) Install PDE: Due to my eclipse setup, I had to install PDE first. You can do this by clicking on the "Europa Discovery" link and you will find the Plugin-Development Editor available there. Also- I had to disable the plugins under "integration".

4) Install Ivy: Click "new remote site", call it "ivy" and use this URL: http://www.apache.org/dist/ant/ivyde/updatesite .
5) Install Spring IDE: Click "new remote site", call it "Spring IDE" and use this URL: http://springide.org/updatesite .

6) Click Finish, go through the dialog boxes, & restart eclipse.

Helpful resources on this:
http://jira.red5.org/confluence/display/docs/Ivy+setup+with+Eclipse
http://springide.org/project/wiki/SpringideInstall