Programming is intrinsically based on the use of limited resources, such as memory and processing power of computers. Various abstractions of resources play an important role throughout computer science, but they are conceptualised in very different, and apparently unrelated ways. In particular, there is a big gap between studies focussing on precise quantitative issues of what we can do and how efficiently we can do it with limited resources, and those which concern more conceptual aspects, which underpin modern high-level programming languages, and application-oriented programming. In this project, building on some recent breakthrough developments which relate these different aspects, we aim to develop a unified theory of resources which will apply to all these aspects, and allow a flow of ideas between them. This will provide new tools and methods for computer scientists, and lead both to new kinds of results, and more general versions of existing ones.