The directory containing the GPLed Java sources for generating Alternating Sign Matrices is here. Download all the files, compile them, and run "java AllASMs n" to generate all $n x n$ ASMs classified according to the attributes $(n,k,m,p)$, where $k$ is equal to $n$ minus the row number of the unit in the last column, $m$ is the number of -1s, and $p$ is the inversion number of the matrix. The program also gives a count $c$ of the number of ASMs satisfying a particular set of attributes $(n,k,m,p)$. It is indicated in the output by "#=c."