A note on Apache POI:This used to be the most reliable and reasonably fast spreadsheet I/O interface SW. But sadly, each major Apache POI release turns out to have become much more complicated in the sense of finding out which .jar files (Java libraries) are needed for Octave. As of Apache 5.x.x, I (= IO package maintainer) have given up on hunting this down. AFAICS for 5.x.x commons-io, log4j-api and maybe others are also required.