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Why RTC with Jenkins?
One answer
Jenkins adds more build functionality. The base build in RTC is the JBE, but it is fairly limited in what it can build. It essentially can execute some kind of script and that is it. Jenkins has many more features to control the build flow as well as open source plugins to customize its configuration.
I would say if you don't know why you would use Jenkins you don't need it, but later if you find yourself pushing up against the limits of JBE you can investigate Jenkins as a replacement.
~Spencer
~Spencer