As you may have noticed, rbutr is only available for Chrome at the moment. This is simply because we are still developing the technology and it just makes sense to start with only one browser and get it right before trying to expand to multiple browsers, where you need to do everything three (or more) times everytime you want to change something.
At the time of writing this, we are about to launch our Beta testing phase(s) – Chrome will be the only browser supported during these phases, but if things go well, then we will expand in to Firefox pretty quickly after the Beta Testing is done. Internet Explorer will probably follow some time later, but we may decided to build frame based options first, so that anyone can access rbutr on demand without the need for a plugin (that is going to be awesome…)
But for now, we’ve got Chrome for testing the concept in, and then the other browsers and more technology will follow as appropriate.
Thanks for helping with the testing!