Open Source OpenBSD Interpreters

newLISP for BSDs, LINUX, MacOS X, SunOS and Win32: small, fast 350+ functions, a -C-, MySQL, PostgreSQL, SQLite, ODBC, TCP/IP, UDP, XML, Java interface, string processing, regular expressions , math, financial, statistical functions, Win32 DLL

Bean Sheet is an interpreted Java spreadsheet. At its core is Bean Shell, an open source Java interpreter. The potential of marrying a Java interpreter with a spreadsheet allows a single document to be a powerful application in its own right.

this is a preprocessor to provide a "national lang support" before the compile-time and then save a lot of run-time. it initially intended to process websites to multiply it with the number of human langs but it is simple enough to use more generally

DaVinci Concurrente es un lenguaje orientado a la enseñanza de la programación estructurada para fortalecer los cimientos base de su aprendizaje, tanto en la etapa inicial de la programación secuencial como en la introducción a los conceptos básicos de la programación concurrente. Permite la visualización de la ejecución a través de una ciudad en la cual se puede controlar uno o más robots. Cada robot puede realizar diferentes acciones (por ejemplo tomar flores en la intersección que se encuentra).

Zoso is a contextual programming language. Contexts speed software development by allowing you to use "mini-languages" that are optimized for specific tasks in a single source code file.

baffle Is an extension to BF language (https://esolangs.org/wiki/brainfuck), which itself in turn is a extension of Turing machine. baffle extends BF by adding a stack, support for procedures, adding more arithmetic instructions, and a register. baffle can run original BF programs, and while it's not the fastest implementation of BF, but it's written in such a way that makes it easier to replace the instruction set, and to write similar languages. Every cell is a single byte, and the tape wraps.