Made exclusively for the new Sidebar API that debuted recently in Opera Developer 29.0.
"Bookmarks by the Side" is a simple bookmarks sidebar extension. The underlying code is a modified version of the "Neater Bookmarks" code by Evan Shultz.
Some stuff from Neater Bookmarks are removed like custom icon (doesn't work with the Sidebar API) and custom style (its hard to wrangle that Codemirror textarea in a sidebar space, plus its a bloat).
Changes from Neater Bookmarks include the style of the tree and the options.
Other functions remain the same, like drag and drop, bookmarks edit and delete etc.