With this extension installed, whenever you select some text in the browser, you can right click to popup the context menu. You will see a menu item called 'Copy to SokoPlayer HTML5'.
To make use of this context menu item, follow these steps:
(1) Select an XSB format level within your browser, for example, at forums or in emails. Please select only the XSB level.
(2) Right click to popup the context menu.
(3) Click "Copy to SokoPlayer HTML5".
(4) Then Firefox will open a new tab and load that level into the online version of SokoPlayer HTML5.
The Add-on icon is created by Borgar under a CC-BY license.