A programming language is perhaps the most direct conduit between human thought and computer logic. Intervening in this space, programmers and artists have created systems of logic and language that explore how strange that transition is. This hacker folk art emerged in the early 90s from Amiga culture, when the bar between professional coders and hobbyists was low, and everything on the machine was a place for creative experiment. The Whitespace language allows one to program using only tab, space, and return. The language Shakespeare asks us to write in a play format, where the positive or negative associations of words control how the machine responds. Other languages read code in the form of photographs, images, or music. Some are only written by mistake; others are impossible to write code in at all.
Furthermore, "esoteric languages" (as they're known) are dematerialized works; collaborative, open-ended, defined by a list of rules rather than any particular implementation. To write code in one is to experience the work while contributing to it. Some take the language far beyond what the original artist intended, or create their own interpreters that expand on the concepts. This is a great model for the potential of distributed, digital art practice.
This exploration of programming languages as a creative medium will focus on concepts and ideas; it is not highly technical -- folks with little programming experience are welcome to join.