Embedded systems have long been synonymous with special purpose, single stakeholder computing. However, as these systems have become more capable and the demands placed on them have become more varied and variable, embedded software is beginning to embrace multi-tenancy. While the general problem of supporting multiple users and processes on a computing platform has been well explored in computer science, the challenges of supporting multiple users with competing desires on a highly energy-variable system remain unexplored. On an energy-harvesting platform, incoming energy needs to be distributed between stakeholders, and users accessing shared platform resources should be charged for the energy use of those resources. Furthermore, with system designers and application creators being increasingly removed from each other, the software environments of energy-harvesting platforms must provide primitives that enable applications to adapt to system variability. We explore several initial techniques for solving these problems and demonstrate them using Signpost—a modular, energy-harvesting platform for city-scale sensing.