This is good news, especially as I’ve noticed recently a lot of developers of browser plugins just creating stuff for Chrome.

The WebExtensions Community Group has two goals:
  • Make extension creation easier for developers by specifying a consistent model and common core of functionality, APIs, and permissions.
  • Outline an architecture that enhances performance and is even more secure and resistant to abuse.
The group doesn't want to specify every aspect of the web extensions platform or stifle innovation. Each browser vendor will continue to operate independently with their own policies.
Source: Apple, Mozilla, Google, Microsoft form group to standardize browser plug-ins | AppleInsider