SDL plc was a multinational professional services company headquartered in Maidenhead, United Kingdom.

[5] In 2007, the company acquired Tridion, a content management system vendor,[6] and PASS Engineering, developers of the Passolo software.

[10] Later that same year, it bought Xopus, another Dutch company and the leader in online XML editing.

[11] In May 2011 SDL acquired Dutch-based Media Asset Management company, Calamares,[12] in 2012 the campaign management and social media analytics company, Alterian,[13] and in 2013, bemoko, a supplier of internet software for mobile devices.

[14] In January 2016, having undertaken a strategic review, SDL announced the divestment of Fredhopper and Alterian as non-complementary to its new strategy.