CodeArchaeology

SmallBASIC is a free, GPL-licensed BASIC interpreter written in C that Nicholas Christopoulos began in 2000 because his new Palm IIIx shipped without a decent calculator - a QBasic-flavoured language small enough for a handheld that, a quarter of a century later, is still being released for Windows, Linux, Android and a Teensy microcontroller

SheerPower (originally SheerPower 4GL, and marketed since about 2020 simply as Sheerpower) is the Windows descendant of Touch Technologies' INTOUCH 4GL for OpenVMS: a BASIC-shaped, database-centric fourth-generation language with a bundled record engine, a bundled web server and a patented decimal math package, given away free by its Southern California vendor for more than twenty years

Sleep is a small Perl-inspired scripting language for the Java platform, written by Raphael Mudge over a weekend in April 2002 so that his Java IRC client could have a scripting engine - and now best known as the substrate of Aggressor Script, the language red teams write inside Cobalt Strike

SimTalk is the object-oriented, event-driven language embedded in the German plant-simulation system that began life as Fraunhofer IPA's SIMPLE, was sold commercially as SIMPLE++ by AESOP GmbH from 1992, and is today Siemens Tecnomatix Plant Simulation - a language almost nobody writes outside a factory model, and one that hundreds of manufacturing engineers write every working day

SETL (SET Language) is a very high-level programming language designed by Jacob T. Schwartz at NYU around 1969-1970, in which finite sets, tuples and maps over arbitrary domains are the primitive data types - the language that produced the first validated Ada compiler and, by way of ABC, gave Python its sets, dictionaries and comprehensions

SIMSCRIPT is the discrete-event simulation language conceived by Harry Markowitz, Bernard Hausner and Herbert Karr at the RAND Corporation in 1962 - the language that gave programming the entity-attribute-set world view, taught Kristen Nygaard's group about pointers on the way to Simula, and still runs the U.S. military's theater-level wargames six decades later