Tofu is a novel application to address the common problem that people don't like reading text on the screen.
Why is that anyway? I believe there are two main reasons: line width and visual instability.
Text is usually very wide on the screen, which makes going from the end of one line to the beginning of the next difficult. That's why newspapers have narrow columns: It makes them faster to read.
So why not just take a normal window and make it narrower, scrolling down as you need? Well, there are usually a lot of lines in a text, and all look more or less the same, so if they move past your eyes vertically, they are difficult to keep track of. The text doesn't feel stable, and you Get lost easily.
In Tofu, text is arranged in columns, and each column is only as high as your window. So lines are nice and narrow, and they don't move about vertically. You just scroll from column to column horizontally, and feel more in control. Bonus: your text is now also in easy-to-digest chunks.
Tofu also includes some other useful features to make reading easier. To search for a word, simply start typing it; Tofu will find to the next matching instance as you type. There's a system-wide Service, so you can quickly move some text from a web page into Tofu. And it lets you navigate using your voice, so you can literally sit back and read.