Apple released their major Mac operating system software upgrade, macOS 10.13 High Sierra, and newest macOS Server on 25th September 2017.
If you wish to jump in immediately and install macOS 10.13 High Sierra, you do so at your own risk as an early adopter - this is a major upgrade to the macOS operating system and there are plenty of major changes this time around (including a new storage format - Apple File System [APFS], a new installation method for some users and new features coming over from macOS Server). There isn't a need to install the new OS immediately - macOS 10.12 Sierra and OS X 10.11 El Capitan are still supported with security updates but OS X 10.10 Yosemite drops off the supported version list. If you're still running OS X 10.10 Yosemite or earlier check out our Securing Older Operating Systems article.
macOS Server 5.4 includes few new features and actually removes a host of features/services - most of these have been moved to the client OS but not all i.e. FTP! If you run macOS Server we strongly suggest you read our macOS Server 5.4 FAQ before upgrading.
We highly recommend holding off on installing macOS 10.13 High Sierra especially if you use your Mac for work/your livelihood - over the next few months Apple will release bug fix updates and third parties will update their software to work with the new OS. On the other hand if you don't and you like the look of some of the new features we've put together some articles all about macOS 10.13 High Sierra and macOS Server 5.4…