Free software to share mouse and keyboard between linux and windows?

I have a doubt, there is a free program to share mouse between linux and windows, I have a PC and a laptop, on the laptop I have w10 and ubuntu mate 18.04, and the pc w10, when I use the PC and laptop with w10, I use the windows software called "Mouse without borders" but it is only for windows, I am looking for a free one for linux and windows, I know that there is sinergy but it is paid

A search on alternativeto (and filtering by Open Source & Linux) returns Barrier, which is forked from Synergy.

There used to be small print on the Synergy website stating that the payment is to download synergy. It's still open source, and you can might be able to build it yourself, but it might need proprietary binaries.

Use Barrier. It is free and open source, was forked from synergy. It is amazing. (Link to GitHub repo)

Installation in newer Ubuntu versions:

Run in a terminal:

sudo apt install barrier

If there is no paackage in your distribution or if you prefer snap packages, you can do instead:

sudo snap install barrier

Installation in Ubuntu 18.04:

In ubuntu 18.04 an alternative way is to first install flatpak:

https://flatpak.org/setup/Ubuntu/

And then barrier using flatpak:

https://flathub.org/apps/details/com.github.debauchee.barrier