Today, Apple released the latest update for macOS. High Sierra 10.13.5 primarily adds Messages in iCloud support, but it also includes some enterprise and security updates. Users of supported Macs can download and install it from the Mac App Store now.

Messages in iCloud has been in the works for a long time, and it has appeared and disappeared from various beta releases of Apple software. It was added in iOS 11.4 earlier this week, and now it's supported on Macs. The feature allows you to store communications you receive and send within the Messages app—plus associated file attachments—in iCloud to save space on your local device. It also means that changes like deleting messages are propagated across devices, and a new Mac that is logged into your iCloud account will immediately have access to your Messages history.

Note that this feature will require you to have some free storage in iCloud, as that service comes with a fee that scales based on the amount of storage you choose.

Here are Apple's release notes for 10.13.5, which also touch on some enterprise updates:

The macOS High Sierra 10.13.5 Update improves the stability, performance, and security of your Mac, and is recommended for all users. This update adds support for Messages in iCloud, which lets you store messages with their attachments in iCloud and free up space on your Mac. To enable Messages in iCloud, go to Preferences in Messages, click Accounts, then select ”Enable Messages in iCloud.” Enterprise content: Variables used in SCEP payloads now expand properly.

Configuration profiles containing a Wi-Fi payload and SCEP payload install as expected when the KeyIsExtractable key of the SCEP payload is set to false.

10.13.5 includes some security updates as well, which Apple has detailed on its support website. For example, the update addresses vulnerabilities in graphics drivers for Intel and AMD chips that allowed applications to read restricted memory, and it fixes a vulnerability in the Mail app that allowed attackers to access the contents of encrypted emails.

The update follows 10.13.4, which among other things added official external GPU support and new privacy features—though we found that eGPU support still has a way to go. Apple is expected to announce the details of macOS 10.14, a more major release expected in September, at its Worldwide Developers Conference on June 4.