Chrome Remote Desktop is fully cross-platform. Provide remote assistance to Windows, Mac and Linux users, or access your Windows (XP and above) and Mac (OS X 10.6 and above) desktops at any time, all from the Chrome browser on virtually any device, including Chromebooks.
This video show installation and setup Chrome Remote Desktop on Windows 8.1 to be shared. And install and setup on Ubuntu to access the shared Windows desktop.
Related: Access shared computer using Chrome Remote Desktop app on Android