With the Session Collaboration feature, users can invite other users to join an existing remote desktop session. To support the Session Collaboration feature, your deployment must meet certain requirements.

Session collaborators
To join a collaborative session, a user must have Horizon Client for Windows, Mac, or Linux installed on the client system, or must use HTML Access.
Windows remote desktops
The Session Collaboration feature must be enabled at the desktop pool or farm level. For information about enabling the Session Collaboration feature for desktop pools or farms, see the Windows Desktops and Applications in Horizon 8 document.
You can use Horizon Agent group policy settings to configure the Session Collaboration feature. For information, see the Horizon Remote Desktop Features and GPOs document.
Linux remote desktops
For Linux remote desktop requirements, see the Linux Desktops and Applications in Horizon 8 document.
Connection Server
For Horizon 8 deployments, the Session Collaboration feature requires that the Connection Server instance uses an Enterprise license.
Display protocols
VMware Blast

The Session Collaboration feature does not support published application sessions.