Today, Microsoft announced that the server SKUs of Office 2019 are available, almost a month after the standard Office apps were released. These include Exchange Server 2019, Skype for Business Server 2019, SharePoint Server 2019, and Project Server 2019.
The new server applications are designed for businesses that aren't yet ready to move to the cloud. The feature set will be somewhere between what Office 2016 users had and Office 365 users currently have. As usual, Office 365 users will continue to get feature updates, and those on the perpetual license (Office 2019) will not.
Unfortunately, while the products are available today, some of them don't actually work. Microsoft notes in its announcement that Exchange Server 2019 requires Windows Server 2019, and like the Windows 10 October 2018 Update, Windows Server 2019 was pulled due to quality issues. In other words, you can pick up Exchange Server 2019 right now, but you can't get the OS to run it on.
Exchange Server 2019 now comes with features like search that's powered by Bing, the ability to restrict the forwarding of meeting requests, and better control for "out of office" settings. Skype for Business gets Cloud Voicemail, Cloud Call Data Connector, Streamlined Migration to Teams, and TLS 1.2. For SharePoint Server, Microsoft is promising "modern libraries, lists, and communication sites". Finally, Microsoft says that Project Server 2019 adds "enhancements to performance and scalability, improved reporting, and an expanded set of APIs".