I used the old ArcExplorer software as a lightweight viewer and mapmaker to publish migratory species distribution shapes on CD. Old Arcexplorer worked offline, but is now incompatible with modern windows versions (it does work in a Linux VM environment). I think it was the best compromise between flexible functionality and rapid learning curves, effective use could be teached in 2 hours! In contrast, the new javabased Arcexplorer is awkward and cannot digest my old arp projects. I think DIVAGIS is still in use, stable http://www.diva-gis.org/ and works offline, so I might use it for the next CD, if I do not get better suggestions.