This is an experimental package which implements an environment, blockarray, that may be used in the same way as the array or tabular environments of standard LaTeX, or their extended versions defined in array. If used in math-mode, blockarray acts like array, otherwise it acts like tabular. The package implements a new method of defining column types, and also block and block* environments, for specifying sub-arrays of the main array. What's more, the \footnote command works inside a blockarray.