A virtual machine for live coding language design

The growth of the live-coding community has been coupled with a rich development of experimentation in new domainspecific languages, sometimes idiosyncratic to the interests of their performers. Nevertheless, programming language design may seem foreboding to many, steeped in computer science that is distant from the expertise of music performance. To broaden access to designing unique languages-asinstruments we developed an online programming environment that offers liveness in the process of language design as well as performance. The editor utilizes the Parsing Expression Grammar formalism for language design, and a virtual machine featuring collaborative multitasking for execution, in order to support a diversity of language concepts and affordances. The editor is coupled with online tutorial documentation aimed at the computer music community, with live examples embedded. This paper documents the design and use of the editor and its underlying virtual machine.