The purpose of "Choice of Kings" is to help you choose an Age of Empires II civilization.
At the top of the page is a table indicating which technologies are available to which civilizations (technologies available to all civilizations are not listed). The top row of the table contains a list of icons representing different technologies (on most browsers, moving the mouse pointer over one of these icons will tell you the name of the technology). The next row contains selector boxes for each technology and this is where you can decide how important a particular technology is by assigning it a value from 0 to 9 (I'll get back to this in a minute). The next 18 rows list each civilization with a picture of a sword in the columns indicating that the civilization does have that technology e.g. there is a picture of a sword under the gate icon in each row except for the one labeled "Goths"; this indicates that Goths cannot build gates. There is also a column labeled score that is blank by default (you'll change that in a minute).
Back to the row with the selector boxes. The values in the selector boxes indicate how important you think a particular technology is i.e. if you think a technology is very important, you should assign it a value of nine, if you think that it is completely irrelevant, then you should assign it a value of zero. Once you are done assigning each technology the appropriate value, you can click on the word "Submit" under the table. The order of the civilizations will change to reflect how well they match the technologies that you wanted (the best matches appear at the top and the worst at the bottom). The scoring system is fairly simple: if the civilization has the technology, it gets as many points as you picked for that technologies selector box. The score is simply the total of all the civilizations points divided by the maximum possible number of points. By assigning appropriate values for each technology, you should get a pretty good idea as to which civilization provides the technologies that you want.
But technologies don't tell you the entire story about a civilization. The bottom of the page contains a list of attributes that are unique to each civilization. You should also consider these attributes when deciding what civilization is best for you. And remember, some civilizations are stronger on some maps than others. For example, if you chose Vikings, the longboat, cheap docks and cheap warships probably won't help you very much on an Arabic map.
Well, good luck. I hope you find this little web application useful and, if you have any comments or questions, feel free to contact me at firstname.lastname@example.org