Carlong was incorporated in 1990 as the successor company to Longman Jamaica Ltd which was acquired by Jamaican entrepreneurs Carl and Shirley Carby, from British publishers, Longman Group Ltd (now Pearson Education Ltd). Shirley Carby had previously managed Longman Jamaica for 14 years.

The company operates from two locations in Jamaica's capital city, Kingston. Executive Chairman, Carl Carby, directs Carlong's Sales, Distribution and Accounting operations from the Warehouse location at 33 Second Street, Newport West. Managing Director, Shirley Carby, directs the Publishing, Marketing and Human Resource Management operations from offices at 17 Ruthven Road, New Kingston.

In addition to developing its own publications under the Carlong imprint, Carlong also provides exclusive marketing and distribution services in Jamaica for textbooks and supplementary readers published under the Longman, Ladybird and Penguin imprints of the Pearson Education Group - EMA Division.

Carlong has produced many publications that have distinguished themselves by their curriculum relevance, sound pedagogy, and creative presentation, which has resulted in many texts being recommended and adopted for use in Jamaican primary and secondary schools, by Jamaica's Ministry of Education, Youth and Culture, and by Ministries of Education for schools in other Caribbean Islands.

In the early years, Carlong developed the first comprehensive primary science and primary social studies series that were designed specifically for the Jamaican curricula. These were adopted by the Jamaican MOEYC, which has for many years distributed them to all primary schools in Jamaica. The MOEYC also adopted Carlong's pioneering comprehensive secondary social studies series for Jamaica's Reform of Secondary Education (ROSE) curriculum. Carlong's major current initiative is the exciting, innovative new series Carlong Primary Integrated Studies (CPIS), responding to the Jamaican MOEYC's newly developed integrated curricula for Grades 1, 2 and 3. This ground-breaking series has now been adopted by the MOEYC for use in all primary schools in Jamaica.

In response to the need for children's literature that supports literacy development and promotes cultural awareness and confidence, Carlong has developed the new Sand Pebbles Pleasure Series. This series is a collection of books featuring Caribbean life and culture, in short stories, chapter books, novels, biographies and other literary forms, for children between the ages of 8 and 12 years old.