How to open and edit multiple projects in the same window in Rider?

Hello, 

Thanks for contacting JetBrains support. 

This feature is also supported in Rider. You can do it via Window | Merge All Soltuion Windows:

Note, with default macOS settings, tabs will be lost after you restart the IDE, and projects will open in separate windows. If you would like the IDE to reopen projects in tabs, configure your macOS to always use tabs when opening documents:
 

Thanks,

Tom

Hello, thanks, Tom!

But I can't find this feature in Rider for the Windows(OS) version.

I only have the actions ‘Next Solution Window’ and ‘Previous Solution Window’ 

Hello, 

This relies on a feature on macOS, so only available on macOS. This is true for both IDEA and Rider. 

Thanks,

Tom

It would be really great if this gets implemented on Windows as well