This Firefox plug-in has been available for some time, and allows users to scroll over a Chinese Character in an online publication with their cursor. This action will bring up a text bubble with the Character pronunciation in Yale, and provide an English definition. It will also recognize groups of Characters that represent words and vocabulary. It is especially useful for individuals that are a little rusty in their Character reading, and need a little helping hand. It is also helpful for intermediate and advanced learners that come across rare characters and vocabulary.
What do people recommend as a Mandarin equivalent?