Javascripting skill required to configure RTC?
Accepted answer
Depending on what you're trying to achieve you will need to know Javascript and Java.
Attribute customisations can be written in Javascript to do things like calculate default values, or derive values from other fields. See this page for more information: https://jazz.net/wiki/bin/view/Main/AttributeCustomization
If you want to do more complex operations then you'll need to use either the server-side or client-side Java APIs to interact with RTC. See this page for more information: https://jazz.net/wiki/bin/view/Main/RtcSdk20
RTC also offers the OSLC API which you can access from any language that has a library for making HTTP requests.