Most up-to-date documentation is bundled with FriCAS. It can be viewed using Hypredoc program. Hyperdoc will be started automatically when you start FriCAS in appropriate graphic emvironment (compatible with X11 windows). Core of FriCAS documentation is updated Jenks and Sutor book ("FriCAS book", former "Axiom book"). Current version in Hyperdoc format is included in FriCAS. Below there is an up-to-date pdf version. Older versions of Jenks and Sutor book are still usable, but miss some changes.