POLAR is released for Windows, MacOS, and Linux. For Linux we provide deb and snap packages as well as static and tar.gz bundles. The full list of downloads is available in our github releases page.
Windows builds require the user to select 'run anyway' after clicking on 'more info' in the security warning images shown below.
We're waiting for Microsoft to approve our digital code signing certificate as part of their Windows Defender program and will hopefully not require this in the future.