DOE has put forth a considerable effort into light-weight kernels for high performance computing, yet there has been a lack of acceptance and use, perhaps due to the limited support for hardware and software. The arguments for lightweight kernels have been based on the problem of interference, i.e. changes in application performance that occur when the operating system pre-empts the application. Nevertheless, using existing, well supported operating systems for HPC systems has been quite successful. The problems with the standard operating systems remain, however, although their impact on applications is still not quantified. At LANL, we have undertaken a research program to determine whether Linux and/or Plan 9 can be used to realize the benefits of light-weight kernels while maintaining the benefits of a full-featured operating system. Specifically, we are evaluating measures that quantify what is ''good'' in a Light-Weight Kernel. We are using this knowledge to modify Linux and Plan 9 to make them competitive with custom light weight operating systems, in essence, a Right-Weight Kernel. This paper represents both a summary of early results as well as a description of work in progress.