Since the late 1980s, the Child Language Data Exchange System (CHILDES) has defined the state of the art of collection, analysis, archiving, and data sharing of transcriptions of children's language. Starting from scratch in 1987, Brian MacWhinney, along with many other leaders in child language, developed highly useful tools for the computerization of transcripts and their analysis. I have used the transcription conventions and analysis programs since 1989 and have seen the system evolve from a simple DOS-based program to one that handles much broader and more complex analyses within more user-friendly Windows and Macintosh platforms. This latest (third) edition of the manual that accompanies the CHILDES system reflects a more stable version of the Conventions for Human Analysis of Transcripts (CHAT) and Child Language Analysis (CLAN) programs than prior editions, which felt like works in progress. This version is written as a finished product with procedures and programs that have settled down into stable patterns of operation.