Common Lisp vs. Emacs vs. JavaScript vs. Unlambda Comparison Chart

At its core is an interpreter for Emacs Lisp, a dialect of the Lisp programming language with extensions to support text editing. Content-aware editing modes, including syntax coloring, for many file types. Complete built-in documentation, including a tutorial for new users. Full Unicode support for nearly all human scripts. Highly customizable, using Emacs Lisp code or a graphical interface. A wide range of functionality beyond text editing, including a project planner, mail and news reader, debugger interface, calendar, IRC client, and more. A packaging system for downloading and installing extensions. Built-in support for arbitrary-size integers. Text shaping with HarfBuzz. Native support for JSON parsing. Better support for Cairo drawing. Portable dumping used instead of unexec. Support for XDG conventions for init files. Additional early-init initialization file. Built-in support for tab bar and tab-line. Support for resizing and rotating of images without ImageMagick.

Unlambda is a programming language. Nothing remarkable there. The originality of Unlambda is that it stands as the unexpected intersection of two marginal families of languages. Functional programming languages, of which the canonical representative is Scheme (a Lisp dialect). This means that the basic object manipulated by the language (and indeed the only one as far as Unlambda is concerned) is the function. Rather, Unlambda uses a functional approach to programming: the only form of objects it manipulates are functions. Each function takes a function as an argument and returns a function. Apart from a binary “apply” operation, Unlambda provides several built-in functions (the most important ones being the K and S combinators). User-defined functions can be created, but not saved or named, because Unlambda does not have any variables.