SplitIndex consists of a LaTeX package, splitidx, and a small program, splitindex. The package may be used to produce one index or several indexes. Without splitindex, the number of indexes is limited by the number of TeX's output streams. But using the program you may use even more than 16 indexes: splitidx outputs only a single file and the program splits that file into several raw index files and calls your favorite index processor for each of the files.