Intelligent fonts are those which alter their appearance depending on their linguistic context.
Computerized typography allows the introduction of aeolotropic fonts, which change their physical properties when their position changes. Thus a character's appearance may be controlled by applying phonetic or grammatic rules. The context dependence of aeolotropic fonts distinguishes them from random fonts which have an aleatoric or random appearance.
An example of an aeolotropic font is Pierre Di Sciullo's "Quantange" which consists of 102 lower case characters and 35 capitals:
Quantange is an orthographic-phonetic-plastic typeface applied to the French language. It is a guide to French pronunciation through graphic correlations between the signs and the sounds, while at the same time respecting the spelling. The text is thus comparable to a music score. In addition to the actual meaning, it indicates the pronunciation, the rhythm and, possibly, the intonation. [...]
The grapheme is the basic unit. One or several graphemes constitute a phoneme, a sound. The same letter [h]as several shapes when, on its own or combined with a group, it changes pronunciation. [...] Sometimes the shape has no justification other than to give the letter some prominence, or for the mere pleasure that it should be so. ("Quantange--Introduction" n. pag.)
With this typeface, unpronounced consonants at the end of words appear as diminutive characters, emphasized syllables are enlarged, and exceptional pronunciations invoke a unique typography. Currently the correct grapheme is selected by the author rather than automatically by the program. Quantange may be said to be aeolotropic but not truly intelligent.
For the literary artist, the possibility exists to control the font by narrative rather than linguistic associations. Different literary characters could speak in different typographic characters. Alternatively, the typeface could depend upon the literary mood or situation. Such typographic innovation would bring new play within the "subtext." How these dependencies could be programmed is not presently clear, however, it is likely that the program would relate the typographic information to stylistic or grammatical analysis engines, many of which are currently available.
Of related interest are two conceptual typefaces designed by British graphic designer and teacher Nick Bell. One is Zelig, a typeface with "the uncanny chameleon-like ability to change its appearance to something very similar to whatever typeface it is placed next to" (Forque 22). Another is Psycho, "[t]he printed version of [which] bears no relation to the words you see on screen. Instead it leaves stab wounds by randomly accessing a cutlery drawer" (Vanderlans 20).