First of all, we need to decide which characters we want the keyboard to produce. Next, we must find out the codes used to represent them, using a program such as Character Map, or with the Character Map in Keyman Developer (go to View, Character Map).

French uses the same 26 letters as English, with some additions. As our keyboard is based on English, we only need to work with these additional letters. Note that for completeness, we will design our keyboard to produce a few other accented vowels that are not used in French. Also, we want our keyboard to include the angled quotes « and ».

These characters, with both uppercase and lowercase forms, are listed in the table below along with their Unicode codes.

Note that you must be careful to use the right character: The Unicode standard has several characters with the same shape as another, but a different meaning; an example of this is the Greek capital letter Sigma and the mathematical summation symbol (). However, an application supporting Unicode would treat them differently. If in doubt whether a character is the right one, you can look up the reference tables at www.unicode.org.

After choosing the characters we want our keyboard to use, we must decide how we want the user to be able to enter them. For some languages, you might replace each letter on the English keyboard with a letter from the language. In this case, however, most of the letters are accented vowels, we will use two keystrokes for each: one for the accent, and one for the vowel.

Now that we have decided which character to use and how the user can enter them, we can start to write the keyboard.