tcbasic implements a small subset of BASIC known as Tiny BASIC.
It provides the following statements and commands: INPUT, PRINT,
LET, GOTO, GOSUB, RETURN, IF, END, CLEAR, LIST, RUN, and STOP. 
Integer and floating point arithmetic is supported, and strings
may be PRINTed. The following built-in functions are provided:
SIN, COS, TAN, COT, ATN, EXP, LOG, ABS, SQR, RND.

The small size of the language make it easy to learn and master
while providing all of the building blocks needed to develop many
interesting programs. tcbasic runs on a variety of platforms and
aims to be as portable as possible.

WWW: https://github.com/tcort/tcbasic