Get Sublime:Though sublime is commercial you can grab an unlimited trial version from here.
It just requests you to buy license one in a while but not at the level to irritate you. The installation is straight forward.
You can download mari Sublime over here... mari-sublime
Download Mari - Sublime:
Extract the archive.
In sublime go to preferences > Browse packages.
Place the extracted folder in the sublime packages folder.
Enable command port in Mari:To execute the scripts inside mari you need to enable the command port.
You can use this script to toggle command port.
mari.app.enableCommandPort( not ( mari.app.commandPortEnabled()) )
If you enable command port you will see a plug icon in the bottom right corner.
Usage:Select a code snippet and press ctrl + m. Only the selected code will be executed in mari. To execute the whole file deselect everything and simply press ctrl + m.
Happy coding !