SooSL is actually two programs that work together closely: SooSL Web and SooSL Desktop.
In SooSL Web, you can use a dictionary that someone else has made and published on the SooSL website. You can use it on any computer, tablet, or smartphone that has a web browser (for example: Chrome, Edge, Firefox, or Safari).
This help file describes both programs. Topics that have "(W)" in their title are about SooSL Web. Topics that have "(D)" in their title are about SooSL Desktop. All other topics are about both programs.