Google has announced the launch of Google Tag Manager, a new tool to consolidate the various tags you may use for your site into one snippet of code, and to manage from a single web interface.
Users can add and update their own tags anytime. It's not limited to Google-specific tags. It includes asynchronous tag loading, so "tags can fire faster without getting in each other's way," as Google puts it. It comes with tag templates for marketers to quickly add tags with Google's interface, and supports custom tags. It also has error prevention tools like Preview Mode, a Debug Console, and Version History "to ensure new tags won't break your site."
There are user permissions and multi-account functionality, and Google says it will be adding more features over the coming months.
Google Tag Manager is launching globally in English, but it will come to other languages soon.
Google has also announced the Tag Vendor Program, which enables tag providers to get templates within Tag Manager.