Apple has released a new version of its OS, named Sierra (or OS 10.12 — turns out that when you reach 10.9 the next logical step is not 11). This new OS introduces several nice additions, such as Siri support, copy and paste between devices, uploading stuff to iCloud (to make room on your disk)... and tabs.
Which brings us to the main issue: Sierra works nicely with Mellel, including the new Tabs feature, which allows you to put all your Docs in a row, so so say. We initially thought about releasing a new version of Mellel that suits Sierra. Currently, there doesn't seem to be a need to do that. All seem to work just fine.