The UiKit uses the semantic version scheme of <major>.<minor>.<patch>. More details can be found here at SemVer.org.
JavaScript
Easily determine the version of the UiKit using JavaScript. wvusUikit.fn.version
will return the version in a string.
alert("The version of the UiKit you are using is " + wvusUikit.fn.version);
// Output
"The version of the UiKit you are using is 2.0.0"