Getting Things Done

David Allen published his productivity methodology in 2001 and it became the foundational text of the knowledge-worker productivity movement, with over 1.5 million copies sold and a devoted global community known as GTD practitioners. Its core contribution — the two-minute rule, the concept of "next actions," and the idea of the mind as a processor rather than a storage device — gave people a systematic way to handle cognitive overload that predated and arguably predicted the productivity crisis of the smartphone era. It has been repeatedly cited by major business and productivity publications as one of the defining books of its genre.