The package defines an environment tabularx, an extension of tabular which has an additional column designator, X, which creates a paragraph-like column whose width automatically expands so that the declared width of the environment is filled. (Two X columns together share out the available space between them, and so on.)

The package is part of the bundle in the LaTeX distribution.

See also tabulary.

The author is David Carlisle. The package is Copyright © 1991-1999 David Carlisle.