Now that macOS Sierra is out, you can use the tabbed window goodness you’re familiar with in Safari and the Finder in pretty much any app. Tabbed app windows are a system-level thing, so there’s a good chance the apps you use every day already support the feature. Read on to see how it works.
To take advantage of macOS Sierra tabbed windows you first need a couple documents open in the same app. Now go to Window > Merge All Windows to group them together as tabs. Once your documents are grouped in a single tabbed window you can click the plus button to the right of the last tab to create new blank documents.
I spend a lot of time working in OmniOutliner, so I’m really glad tabbed windows work there. They don’t, however, work for me in BBEdit—another app I use daily. That’s most likely because BBEdit uses its own document list to keep everything in a single window.
Apps that don’t offer text formatting, like Maps, can typically use Command-T to create new tabs, as well. Command-T also opens the text formatting window, so good job on doubling up the function of a system-wide keyboard shortcut, Apple.
Tabbed document groups work just the same as tabs in Safari, so you can switch documents with a click, and drag to rearrange them, too. Considering how many documents I have open, macOS Sierra tabbed windows should free up a lot of screen space for me.