A LaTeX document class for articles that is tailored to the design of American Mathematical Society journals. If you have a standard installation of LaTeX, you should find that amsart is already present because it is included in the AMS-LaTeX distribution. For publication-specific AMS document classes (jams-l.cls, bull-l.cls, tran-l.cls, proc-l.cls, mcom-l.cls, etc.), see http://www.ams.org/tex/author-info.html. The author is American Mathematical. See also amslatex.