The Extended Speech Assessment Methods Phonetic Alphabet (X-SAMPA) is a variant of SAMPA developed in 1995 by John C. Wells, professor of phonetics at University College London.
[1] It is designed to unify the individual language SAMPA alphabets, and extend SAMPA to cover the entire range of characters in the 1993 version of International Phonetic Alphabet (IPA).
SAMPA was devised as a hack to work around the inability of text encodings to represent IPA symbols.
However, X-SAMPA is still useful as the basis for an input method for true IPA.
Shaded areas denote articulations judged impossible.