Essence of open source

Glass with engraved OSI logo containing distilled spirits

We’ve been trying to distil a succinct phrase that captures the generally-accepted core understanding of “open source software”. The best so far is:

Open source software is software which people everywhere are able to use, improve and share in any form and for any purpose without essential ex ante or post hoc negotiation with rights holders.

Obviously the use of an OSI-approved license guarantees that. How could we make the phrase shorter, clearer or more accurate?

Update on June 25:

This phrase seems to capture a lot of what we’re after:

It’s “open” if the work product can be used, improved and shared, for any purpose, without undue obstruction or required negotiation.

This has the advantage of not attempting to redefine any of {Open Source, Open Data, Open Hardware, Open Silicon} while also conveying the key attributes each of them must have before anyone should consider them open.

More improvements invited!

Update on July 8:

Deleted “undue” as discussed as I couldn’t think of any applicable “due” obstruction. So we have:

It’s “open” if the work product can be used, improved and shared, for any purpose without obstruction or required negotiation.

That’s now worked well in several places so we may have it here!