Direct answer
Focused software with a bounded purpose, small operational footprint and an explicit path to ownership and exit.
Why it matters
Small tools are easy to create but often abandoned when deployment ownership and maintenance remain implicit.
Scope
A stable concept used by Service Cards, deployment contracts and the SmallGreen Spec.
Out of scope
It is not a guarantee of security, permanence or universal compatibility.
How it works
Bound the purpose declare the resource budget publish the deployment contract and keep a tested exit path.
Example
A URL shortener with one deployment contract one evidence trail and a complete teardown path is Small Software.
Machine-readable references
SmallGreen Spec · cards.json · llms.txt
Evidence and limitations
The label describes scope and operability only. It does not prove security reliability or community adoption.
Related concepts
The ownership and deployment layer · What is a Deploy Agent? · What is a Service Card?
Version
Concept v1.0 · SmallGreen Spec v0.2.1