The package provides an environment, tabu, which will make any sort of tabular (that doesn't need to split across pages), and an environment longtabu which provides the facilities of tabu in a modified longtable environment. (Note that this latter offers an enhancement of ltxtable.)

The package requires the array package, and needs e-TeX to run (since array.sty is present in every conforming distribution of LaTeX, and since every publicly available LaTeX format is built using e-TeX, the requirements are provided by default on any reasonable system). The package also requires xcolor for coloured rules in tables, and colortbl for coloured cells. The longtabu environment further requires that longtable be loaded. The package itself does not load any of these packages for the user.

The tabu environment may be used in place of tabular, tabular* and tabularx environments, as well as the array environment in maths mode. It overloads tabularx's X-column specification, allowing a width specification, alignment (l, r, c and j) and column type indication (p, m and b).

\begin{tabu} to <dimen> specifies a target width, and \begin{tabu} spread <dimen> enlarges the environment’s “natural” width.