The Tiny BASIC language specification was designed by Dennis Allison for the first microcomputer systems that emerged in the mid 1970s. It is one of the earliest examples of free, open source, collaborative software. It was developed in response to the expensive Altair BASIC sold by Microsoft. Compared to other microcomputer basics of the era, the Tiny BASIC specification had a limited set of features, omitting string handling and floating point numbers. Extensions to the Tiny BASIC language added extra features, including arrays, FOR loops and user defined functions.

Implementations of Tiny BASIC were published as source code and binary listings. Dr Dobbs journal began in order to publicise Tiny BASIC development.

One of the most popular implementations of Tiny BASIC was Palo Alto Tiny BASIC (PATB) by Li-Chen Wang. It supported loops with FOR/NEXT/STEP, it had a single array variable @, and it fit within 2K.

Over the next few years, when computer memory was expensive, derivatives of PATB could be found in some commercial computer systems including the TRS-80 and the Transam Triton.

A combination of factors made Tiny BASIC redundant: memory became cheaper, and new microcomputers had their own BASICs built in that could take advantage of the specifics of their hardware.