Yabasic is a free MIT-licensed BASIC interpreter for Windows and Unix, still actively maintained, with optional line numbers, GTK GUI support, and standalone executable bundling.
Key Takeaways
Latest stable release is 2.91.4 (August 2025); source lives on GitHub under MIT License since version 2.77.1.
Supports structured programming: named subroutines, local variables, return values, and code modules with separate namespaces; no composite data structures.
Can bind a program to the interpreter to produce a single-file standalone executable.
Sony shipped Yabasic on PS2 demo discs in PAL regions to classify the console as a home computer, bypassing European import taxes.
GTK-based GUI option available; a FLTK port (Flyab) was attempted for cross-platform native UIs but development halted circa 2008.
