Perhaps surprisingly, two fierce Apple competitors were given the opportunity to tout their extensions first and foremost, namely Amazon.com with their Wish List extension and Microsoft with their Bing Extension for Safari. Also featured in the press release: MLB.com, The New York Times and Twitter (eBay also gets featured on the Gallery site).
The new Safari Extensions Gallery is accessible straight from the browser menu or at extensions.apple.com. Users can download and install extensions from the gallery with a single click, and there’s no need to restart the browser (much like Google Chrome, and unlike Firefox).
I did a quick count and came out at above one hundred extensions already.
Add-ons can be automatically updated and are managed within Safari. Users can enable or disable individual extensions, or turn off all extensions with one click.
Every Safari Extension comes signed with a digital certificate from Apple to “prevent tampering” and to verify that updates to the extension are from the original developer. Safari Extensions are also sandboxed, which prevents them from accessing information on a user’s system or communicate with websites aside from those specified by the developer.
As Apple had made clear earlier, Safari Extensions run solely in the browser.