One of the hardest parts of building a web site with a simple text editor is encoding special characters. Entities are easy enough to use, but remembering them is not. I have used several reference charts, but I have not been able to find one that I like. So I did what I usually do when I can't find something that solves a problem. I wrote a program to solve it myself.
This is a work in progress. Right now it shows you the information you need and lets you filter the list based on the type of character you want. Eventually I will add more powerful filters, etc. I have found it useful many times in its present state, though.