Gmail's Labs used to be a testing ground for advanced features, but many have moved or retired over time. Some features like canned responses, auto-advance, and undo send are now built-in or under the Advanced header. The Auto-Advance Lab can help process your inbox faster by automatically advancing to the next message after deleting or muting a conversation. Canned responses, also known as templates, allow you to create quick replies with links, while custom keyboard shortcuts and an unread email count on the Gmail favicon offer additional productivity features. The preview pane has been re-added as a button in the main interface, allowing for vertical or horizontal splits. Multiple inboxes can be customized using advanced search functions, making it a power user's dream to tailor their inbox to their needs.