RDNG - Offline mode
Accepted answer
Liora.
There's no RDNG offline client, nor plans to build one as far as I know.
Lately I've seen increased activity in some WIs to improve the way imports/exports are done so that's the direction Rational seems to be taking regarding offline collaboration.
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https://jazz.net/jazz03/resource/itemName/com.ibm.team.workitem.WorkItem/44296
https://jazz.net/jazz03/resource/itemName/com.ibm.team.workitem.WorkItem/72827