Windows Server 2016 Technical Preview Resource from Hardware vendor

HP
Implementing Microsoft Windows Server 2016 Technical Preview 4 on HPE ProLiant servers - In non-production environments for testing
http://www8.hp.com/h20195/v2/GetPDF.aspx/4AA5-5841ENW.pdf

DELL
Microsoft Windows Server 2016 - Technical documentation and guidance for Windows Server 2016
http://en.community.dell.com/techcenter/os-applications/w/wiki/11735.microsoft-windows-server-2016
Running Windows Server 2016 on Dell Servers in Non-Production Environments
http://en.community.dell.com/techcenter/os-applications/w/wiki/11743.running-windows-server-2016-on-dell-servers-in-non-production-environments

Lenovo

Start Your Engines for Windows Server 2016 on Lenovo Servers
http://blog.lenovo.com/en/blog/start-your-engines-for-windows-server-2016-on-lenovo-servers/
Introduction to Windows Server 2016 Nested Virtualization
https://lenovopress.com/lp0087.pdf
Introduction to Windows Server 2016 Nano Server
https://lenovopress.com/lp0082.pdf

Windows Server 2016 Technical Preview Resource from Hardware vendor