On Mac OS X, the Character Viewer (equivalent to Character Map on Ubuntu) has a feature where, when looking at a certain character, it can show a list of all fonts that contain that character. Is there something equivalent on Ubuntu?
The use case is that, for instance, I could click on a Kannada character and see all fonts that cover that character (and presumably, the rest of the Kannada language range).
Edit: Just for an idea of what I mean, here's a screenshot of Character Viewer on Mac OS X 10.6. The "Containing selected character" is near the bottom of the screen. I seem to remember that this part of the interface was better in 10.5 or 10.4, actually.
Best Answer
In Fontmatrix you can compare font characteristics - In the Font Information - Compare.
PS. I think that feature of Character Viewer on Mac OS X would be an awesome feature request to ask of the fontmatrix developer team.
In fact, the interface of Fontmatrix has something even better: you can select the Preview tab and enter a string (containing characters you would like the font to have), and see how it is displayed by each font. So you can scroll through the list of fonts and simultaneously see the fonts' coverage of all the interesting characters, instead of just one character at a time. This helps you visually pick out the fonts containing the selected character(s).
In the screenshot below, you can see that "BABEL Unicode Bold" (selected) contains all characters except ṝ and that "Arial Regular" (where the mouse is) contains only a few characters.