ScanFont is a very special kind of font editor. It includes an image editor (with the ability to edit images in any zoom mode and multiple undo/redo), autotracer and middle-class vector font editor.
It has a very easy drag-drop interface and a number of easy-to-use toolbars. ScanFont is a font editor for people who never need to edit vector fonts with sophisticated applications like FontLab or Fontographer. You can use the image editor to create your characters, or draw them on paper and scan them then trace and place them into a font.
However, if you don't plan to use ScanFont to scan fonts, we recommend you to use TypeTool, which doesn't include font tracing features but is less expensive—or FontLab Studio / FontLab VI, which have more sophisticated font creation capabilities.
Also, note that ScanFont is no longer being developed: much of its capabilities are being integrated into FontLab VI.