Ax helps you to save off and later restore a working state of your computer in Ubuntu.
It does this by numerous plugins, usually one for each program whose state you intend to save and restore. Each plugin is responsible for its program and remembering all pertinent details. Which details are pertinent are of course up to the plugin writer.
The name "Ax" is just a shortening/abbreviation-thingy of "anti anxiety", paying homage to the pools of sweat I'd collect when I'd think about how long it'd take me to restart my computer and get everything set up back up to where I had left it. I can't believe there's no tool existing like this out there. The closest I've seen is Mac OS X which actually does a pretty good job. But other than that, the world is bleak in the world of Linux (and Windows from the last time I used it).