[grumpyprole]

> and hints at backwards compatibility.

To me it communicates no commitment to backwards compatibility, i.e. no semantic versioning. This might be enforceable if one is Apple, but doesn't sound good for an open-source platform.

[bryanlarsen]

To me it communicates a commitment that they'll never have any significant breaking change ever again without changing their name, fork style.

[npteljes]

Yeah like how Firefox got rid of XUL extensions in version 57.

[willtim]

An insignificant breaking change is still a breaking change; and over time they build up. This may explain why so many developers have been unhappy with GTK3.

[geofft]

What would semantic versioning for a UI even mean? What's the API promise?

[xorcist]

It could mean that all applications still run unmodified and can show all the dialog boxes they used to.

That may not sound like much of a promise, but it is. Applications written for GNOME 2.x won't run under 3.x.

[aembleton]

x.y.z

x would increment on the removal of a feature

y would increment on the addition or change of a feature

z would increment on a bug fix