Like most browsers, Firefox keeps a history of your browsing activity so you can find sites you visited previously.
However, Firefox is pretty light on historical details, such as when you visited a particular site and where you went from there. That lack of chronology can make it difficult to find what you're after.
Enter History Tree, a Firefox add-on that gives you a visual overview of your browsing history. You can view this history as either a tree (hence the name) or a grid of site thumbnails. Click the image at right to see an example of the former.
After installing the add-on, just click Tools, History Tree to open the view in a new window. What you see may seem a little confusing at first, which is why I recommend skimming the developer's tutorial.
I'll admit that I rarely use the history feature in Firefox or any other browser, as I tend to rely more on tools like Toread and PermaTabs. But I can definitely see the appeal of History Tree, which makes retracing your Web steps a lot easier and more informative.