https://developer.mozilla.org/en-US/docs/Web/API/WorkerNavigator/language
WorkerNavigator: language property - Web APIs | MDN
The WorkerNavigator.language read-only property returns a string representing the preferred language of the user, usually the language of the browser UI.
web apislanguagepropertymdn
https://developer.mozilla.org/en-US/docs/Web/API/WorkerNavigator/appVersion
WorkerNavigator: appVersion property - Web APIs | MDN
Returns either "4.0" or a string representing version information about the browser.
web apisappversionpropertymdn
https://developer.mozilla.org/en-US/docs/Web/API/WorkerNavigator/deviceMemory
WorkerNavigator: deviceMemory property - Web APIs | MDN
The deviceMemory read-only property of the WorkerNavigator interface returns the approximate amount of device memory in gigabytes.
web apispropertymdn
https://bugzilla.mozilla.org/show_bug.cgi?id=925846
925846 - [meta] WorkerNavigator should be feature complete according to HTML 5 spec
RESOLVED (nsm.nikhil) in Core - DOM: Workers. Last updated 2016-03-16.