We apply the biological-behavioral concept of an umwelt, which is how an organism perceives and acts within its environment, to the practice of software development. By writing narrative descriptions of our own software umwelts and iteratively discussing and analyzing them, we develop prompts that can elicit reflection on how and why we relate to software in the ways that we do.

How a sidekick scripting language for Java, created at Netscape in a ten-day hack, ships first as a de facto Web standard and eventually becomes the world's most widely used programming language. This paper tells the story of the creation, design, evolution, and standardization of the JavaScript language over the period of 1995--2015. But the story is not only about the technical details of the language. It is also the story of how people and organizations competed and collaborated to shape the JavaScript language which dominates the Web of 2020.

We performed an empirical study to understand how different language features are used by JavaScript developers in practice, with the goal of using this information to assist future extensions of JavaScript. We inspected more than one million unique scripts (over 80 million lines of code) from various sources: JavaScript programs in the wild collected by a spider, (supposedly) better JavaScript programs collected from the top 100 URLs from the Alex a list, JavaScript programs with new language features used in Firefox Add-ons, widely used JavaScript libraries, and Node.js applications. Our corpus is larger and more diversified than those in prior studies. We also performed a study on 45 JavaScript developers to understand the reasons behind some of their language feature choices. Our study shows that there is a wide-spread confusion about newly introduced JavaScript features, a continuing misuse of existing problematic features, and a surprising lack of adoption of object-oriented features. Understanding JavaScript programming practices will assist many stakeholders: tool developers can analyze the requirements of better tools and more responsive IDEs and programmers can learn about the used (and the good) parts of JavaScript.

This paper introduces the programming language Modular Smalltalk, a descendant of the Smalltalk-80 programming language. Modular Smalltalk was designed to support teams of software engineers developing production application programs that can run independently of the environment in which they are developed. We first discuss our motivation for designing Modular Smalltalk. Specifically, we examine the properties of Smalltalk-80 that make it inappropriate for our purposes. We then present an overview of the design of Modular Smalltalk, with an emphasis on how it overcomes these weaknesses.

QUICKTALK is a dialect of Smalltalk-80 that can be compiled directly into native machine code, instead of virtual machine bytecodes. The dialect includes “hints” on the class of method arguments, instance variables, and class variables. We designed the dialect to describe primitive Smalltalk methods. QUICKTALK achieves improved performance over bytecodes by eliminating the interpreter loop on bytecode execution, by reducing the number of message send/returns via binding some target methods at compilation, and by eliminating redundant class checking. We identify changes to the Smalltalk-80 system and compiler to support the dialect, and give performance measurements.