I think the best option for a Rel IDE would be to create a plugin for Eclipse Data Tools Platform (DTP) Project to add support in Eclipse for Rel.
I guess the initial guide is here, sadly I have no experience in creating this kind of stuff
![Sad :(](./images/smilies/icon_sad.gif)
![Wink :wink:](./images/smilies/icon_wink.gif)
Regards,
LuxSpes