Scripting is often used in science to create applications via the composition of existing programs. Parallel scripting systems allow the creation of such applications, but each system introduces the need to adopt a somewhat specialized programming model. We present an alternative scripting approach, AMFS Shell, that lets programmers express parallel scripting applications via minor extensions to existing sequential scripting languages, such as Bash, and then execute them in-memory on large-scale computers. We define a small set of commands between the scripts and a parallel scripting runtime system, so that programmers can compose their scripts in a familiar scripting language. The underlying AMFS implements both collective (fast file movement) and functional (transformation based on content) file management. Tasks are handled by AMFS's built-in execution engine. AMFS Shell is expressive enough for a wide range of applications, and the framework can run such applications efficiently on large-scale computers.Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than the author(s) must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from Permissions@acm.org. SC13