Unicode Character Keyboard

Furthermore, I wanted to learn WordPress plugin design (having done MediaWiki plugins in the past) because I really like the WordPress platform and this seemed like a perfect tool not only to learn all of the various details of plugin design but also give something back to the WordPress community.
How do I add character set {X}?

First off, make a list of all the character definitions that make up the desired character set. Second, divide them up into named categories and under that, contiguous sub-groups. (See the existing definition files for examples.) The categories are what show up under the sub-headings and the groups are how the rows are divided up in the display. In addition, select which existing type of character sets the new set will fall under, or define a new type for use with this set, and write a comprehensive description of the character set. Optionally, include the location of the Unicode character definition PDF file and the defined character set range information.
Next, code the definitions and the additional information into an XML file. The Customize menu sub-page provides information on writing the character set XML definition file, including a breakdown of each XML element and showing the template XML and DTD files and the Common XML definition file. Other XML files can be examined using the plugin editor menu sub-page. Be sure to give the character set and the definition file a unique name, and remember to use only characters, numbers and spaces in the set name.
Use the Manage File menu sub-page Upload tab to upload the file into the custom module subdirectory, then check the Error Log tab to see what errors or warnings were found in the file: if any errors were found, the file will not be loaded into the module subdirectory. Warnings, on the other hand, are problems in optional sections of the definition file and do not prevent loading.
Use the Setting menu sub-page to activate the character set.
Use the Display menu sub-page to view the character set.

I would ask that if you create a new character set to send it to me so I can add it to the distribution.
All this character set stuff is hard to figure: can you recommend any references? What all is available?
There are a number of references to the Unicode character codings available.

Unicode Standards
Unicode Character Code Charts
HTML 4.01 Character Entity References
HTML ISO-8859-1 Reference
HTML - Special Entity Codes
Sacred Texts Unicode list

The first line is Conway's Game of Life programmed in the APL language.
The second line are the astrological symbols for the 12 houses of the Zodiac.
The third line are the numbers 1 to 4 in Japanese.

The Symbola font was used to represent the various symbols in the image, which is also the font used to display them in the browser. All of these characters are available through the Unicode Character Keyboard metabox.