Es shell

What it does

Availability

The page links to a download for es 0.9.2.checked 14 Nov 2026

Copyright and distribution

Es is stated to be public domain, with no copyright or patent restrictions on distribution.checked 14 Nov 2026

Extensibility

Built-in services such as path searching and redirection can be modified or extended.checked 14 Nov 2026

First-class functions

Es supports first-class functions.checked 14 Nov 2026

Language origins

Its language derives from the Plan 9 shell rc and was influenced by Scheme and Tcl.checked 14 Nov 2026

Maintenance

The site says James Haggerty maintains it after 0.9beta1.checked 14 Nov 2026

Manual description

The manual describes Es as a command interpreter and programming language combining Unix-shell and functional-language features.checked 14 Nov 2026

Product

Es is an extensible shell and command interpreter intended for interactive use and scripting.checked 14 Nov 2026

Project status

The site says Es had its heyday from 1993 to 1996 and that its mailing list was apparently last active in 2002.checked 14 Nov 2026

Quoting

The site describes Es's quoting rules as less baroque than those of C or Bourne shells.checked 14 Nov 2026

Return values

Functions can return values other than numbers.checked 14 Nov 2026

Scope and errors

The site lists lexical scope and exceptions as shell features.checked 14 Nov 2026

Variables

Es exports user-defined variables to the environment unless explicitly told otherwise.checked 14 Nov 2026