Subsequently is an attempt at designing a live programming environment that is deeply visual, tangible and concrete. In Subsequently, you create programs by directly manipulating concrete, visual representations of data values, operations and control flow. All these different aspects are represented on screen as a diagrammatic comic strip. By simply manipulating concrete values step by step, the programmer creates a rich visual narrative that acts both as an executable program and a legible explanation of the algorithm. Because the program is represented concretely, there is no explicit “run” step or debugger. All program state is immediately visualised as you go.