Yabasic

Yabasic (Yet Another BASIC) is a free, open-source BASIC interpreter for Microsoft Windows and Unix platforms. Yabasic was originally developed by Marc-Oliver Ihm, who released the last stable version 2.77.3 in 2016. From version 2.77.1, the project has adopted the MIT License as well as the source code being moved to GitHub to encourage others to participate in its development.

Features

 * No line numbers
 * Line graphics in color
 * Structured programming—various block structures, named subroutines with local variables and return values
 * Code modules/libraries with separate namespaces (On the other hand, composite data structures are missing)
 * Option to use a graphical user interface based on the GTK library
 * Self-modifying code
 * "Binding" a Yabasic program to the interpreter, creating a standalone executable in a single file

Yab
A version optimized for BeOS, ZETA and Haiku.

Flyab
A port of Yabasic to the Fltk toolkit called "Flyab" was under development. It would have been source-compatible with programs written in yab, a variant of Yabasic that enables graphical programs to be written using the BeOS API. After BeOS and its successor ZETA finally were gone, the team members around yab for BeOS decided to move to Linux and therefore chose FLTK to implement the UI parts. Ports for Microsoft Windows, Mac OS X, and Linux would have been possible. Flyab added the ability to Yabasic to create native graphical user interfaces on all supported platforms. Main difficulty was to fully implement the layout commands to FLTK, as used from the BeOS version. As of November 2008, the project appears to be halted.

PlayStation 2
Sony also packaged a version of Yabasic for the PlayStation 2 on the demo disc shipped with PS2 consoles in PAL territories so it could be considered a home computer, not just a games machine, thus bypassing European import taxes.

Yabasic 3.0 (Unofficial)
As a continuation of the project prior to new changes by the original author, version 3 was being developed by a team centered on Pedro Sá and Thomas Larsen, but development has halted and the project now appears to be abandoned.