Official browser extensions are available for Chrome and Firefox. They provide a toolbar button to bookmark the current page. The Chrome extension should work on Opera as well, just install the Download Chrome Extension first.
Currently extensions for other browsers are not planned. Anyone is free though to write and release additional unofficial browser extensions – either for other browsers or alternatives to the official ones. See below for a description of the API available to extension authors and see bort-extensions at GitHub for the source code of the above extensions, available under the MIT license.
Currently the only “API” provided for developers is URL-parameters to add a bookmark. This will take the user to the Bort.io web page to interactively add the bookmark and once done, redirect back again.
URL and TITLE should be passed through
encodeURIComponent to ensure proper
escaping and evaluation. If given, TAGS should be separated by pluses, e.g. "news+comics".
See the above extensions and bookmarklets for examples of using this API.