A phonetic alphabet created by English and French phoneticians. Most letters are taken from the Roman alphabet or derived from it, some are of Greek origin and there are some letters apparently unrelated to former letters.
The sound-values of the letters are in some cases identical with French and/or English usage; e.g. [z] has the same sound as in English ZINC or French ZRO. [j], on the other hand, has the sound value of English Y in YOKE; whereas [y] has its Scandinavian and Old English value.
Vowels in general tend to be close to Latin and Italian, [e] is closer than English /e/ in MET, /i/ is the vowel sound found in English MEET; and so on.
The official homepage of the International Phonetic Association shows all the letters.
See also: SAMPA for a method of mapping IPA designations into ASCII, without losing information.