Unfortunately, E4 does not yet support multi-user environments. Writing
a renderer for RAP is simple, but the e4 bugs collected in  are real
But there may be an interesting alternative for RAP applications: if we
could support the most important annotations that are used in E4, that
would enable you to write code that runs on Eclipse 4 and also on RAP,
maybe with a different, light-weight UI model. That's something we plan
to look into soon.