This 2-volume proceedings contains 73 papers from November 2000 conference, covering a wide range of areas in language acquisition and language development. The volumes include the keynote address by Lois Bloom, the plenary address by Nina Hyams, and a historical overview and analysis of the BUCLD conference by Margaret Thomas. The complete table of contents and other details can be found on our web site at http://www.cascadilla.com/bucld25toc.html along with easy on-line ordering.