When you have narrowed down your search results to maybe a dozen of fonts, you might like to compare them side by side.
Go to Playground tab in the main window.
Fontmatrix takes a somewhat unusual step away from a traditional table way of laying out text lines rendered with different fonts. What is suggests instead is a huge zoomable comparison area where you can drag text lines around, freely regroup them and pan around.
Contrary to Sample Text tab playground always uses native Qt font rendering engine, so you can freely zoom in and out and never see ugly pixel blocks.
Having added a dozen of text lines rendered with different fonts you surely might not remember which one is which. Just hover on a text line to see a tooltip saying which font font was used. Location and name of the font comes as a bonus.
To move around a rendered line of text just click on it and drag to wherever you want it to be. If you want to move several lines of text, press Ctrl and keep clicking on text lines until your group is selected or, if they are already nicely layed out, draw a rubberband frame around them to select them. Then drag them all elsewehere. To remove current selection just press Escape or click on blank space outside any text line.
Navigation in the comparison area is easy: press middle mouse button to pan and use Ctrl+mouse wheel to zoom in and out. You can even do both having a selection of text lines.
To remove existing text lines select them and press Delete.