TESOL

TESOL is an acronym for Teaching English to Speakers of Other Languages. Related Wikipedia articles include:

ESL/ESOL/EFL/ELT - most information is concentrated in this article
Teaching English as a Foreign Language (TEFL) - this article concentrates on travel-teaching
Language teaching - the teaching of languages generally
CertTESOL - a certificate awarded by Trinity College, London
LTCL DipTESOL - Trinity Licentiate Diploma, a diploma awarded by Trinity College, London
TESOL Inc. - a large U.S.-based organization for teachers of ESOL