Technical Dimensions of Programming Systems

Programming requires much more than just writing code in a programming language. It is usually done in the context of a stateful environment, by interacting with a system through a graphical user interface. Yet, this wide space of possibilities lacks a common structure for navigation. Work on programming systems fails to form a coherent body of research, making it hard to improve on past work and advance the state of the art. In computer science, much has been said and done to allow comparison of programming languages, yet no similar theory exists for programming systems; we believe that programming systems deserve a theory too. We present a framework of technical dimensions which capture the underlying characteristics of programming systems and provide a means for conceptualizing and comparing them. We identify technical dimensions by examining past influential programming systems and reviewing their design principles, technical capabilities, and styles of user interaction. Technical dimensions capture characteristics that may be studied, compared and advanced independently. This makes it possible to talk about programming systems in a way that can be shared and constructively debated rather than relying solely on personal impressions. Our framework is derived using a qualitative analysis of past programming systems. We outline two concrete ways of using our framework. First, we show how it can analyze a recently developed novel programming system. Then, we use it to identify an interesting unexplored point in the design space of programming systems. Much research effort focuses on building programming systems that are easier to use, accessible to non-experts, moldable and/or powerful, but such efforts are disconnected. They are informal, guided by the personal vision of their authors and thus are only evaluable and comparable on the basis of individual experience using them. By providing foundations for more systematic research, we can help programming systems researchers to stand, at last, on the shoulders of giants

Ascending the Ladder to Self-Sustainability: Achieving Open Evolution in an Interactive Graphical System

Programming is usually based on an inconvenient separation between an implementation level and a user level. Selfsustaining systems expose their implementation at their user level so that they can be modified and improved from within. However, the few examples that exist are tightly linked to textual language-based accounts of compiler bootstrapping. If we want systems to be truly open for modification, we need to step beyond programming languages and support more structured, visual ways of programming as well. How the bootstrapping process can work in such an interactive context is important yet unexplored territory. This essay is a critical report on our first-hand experience of building one such system named BootstrapLab. We trace and reconstruct the steps for achieving self-sustainability in an interactive, structured, graphical context: choose the platform; design the substrate; implement temporary infrastructure; implement a high-level language; pay off outstanding substrate debt; provide for domain-specific notations. Throughout, we discuss the challenges involved, identifying design forces that shaped the decisions and capturing heuristics that resolved these forces in our case. Both positive and negative results are featured, including the efficacy of the heuristics. We close by suggesting how to generalise what worked in our particular case to alternative paths and starting points. The enterprise as a whole takes us a further step towards achieving open and malleable programming systems for everyone