❌ is no longer maintained :(

更新がないために移行します

The only and best add-on for the declared purpose.

Several years ago the developer stopped supporting his plugins to focus on Thunderbird. I hope he isn't the one responsible for how bad Thunderbird is now, because if so he should have stuck to plugins.

>3. Open a command prompt. Run the file with the argument "install", like this:
>open_with_windows.py install
>If you move the file, you must run this step again.

Note for the noobs like me: The command should be:
python open_with_windows.py install

Works well, just follow the installation instruction (native client)

Used to be one of my favorite addons. Did not use it for a long time.

Discontinued by developer, so move onto something else. And it no longer works, and no point in trying to find out why.

Works like charm.

As noted in the "About this extension" section and on the Github repo, this is no longer maintained as of 2022. Further, it doesn't seem to work for many people. For myself, it doesn't work on an m2 mac with Firefox 114.

Could not get the extension to work. No debug codes were given in the firefox browser console, python console or CMD console

The addon is now archived (no more updates).
If it breaks in the future try the following alternative addon:
External Application Button
(by Andy Portmen)

I heard that the "Open With" developer no longer maintains the extension (I hope that some developer continues to update and maintain the extension, as it is very useful to open YT-DLP and video players such as MPV, PotPlayer, VLC and MPC- HC)