Drupal Views now comes with a contextual filter that filters content by the first letter, which is a great feature. But it's a contextual filter, not a regular filter. If you start experimenting with the glossary view, which using this feature, you'll notice it places the letter in the url and changes pages. You can't use it for ajax filtering and you can't use it easily with other filters, or as an exposed filter. That's exactly what I needed, an exposed filter, so I built a module to handle this problem.
