The evaluation SDK can be used to create Linux and file system images that can be redistributed (as the kernel and applications source), but the build system includes parts that belong to RidgeRun and cannot be redistributed without permission.
Your hardware may have a maillist or forum suppost, such as http://www.DesignSomething.org, where you can post questions. RidgeRun regularaly updates http://developer.ridgerun.com with informtion on how to resolve common problems.
RidgeRun's SDK is designed to simplify and reduce embedded Linux development time, by integrating functionality in easy to use environment. It also provides improvements over other solutions like smaller footprint or Real-Time patches. Check product page of your interest for more information of the features supported by the SDK in specific hardware.
RidgeRun also provides a complete solution set for your Linux product, beyond the basic OS and drivers.