How do I install Enlightenment on Mint 15? I got this far:

sudo apt-get install e17

And it seemed to succeed, but nothing changed. Obviously there's another step, but none of the instructions I've found anywhere say what it is.

Mint 15 is 'end of life', 'out of support'. So you should upgrade or install a newer version (or mint 13, its supported until april 2017)

http://www.linuxmint.com/oldreleases.php

If you have e17 installed, you'll need to select it from the login screen.

When you've installed a second desktop, you have to select it: this thread explains it:
http://forums.linuxmint.com/viewtopi...f=206&t=118855

Geez, already?! It was the *newest* version available when I installed it, and that wasn't long ago at all.

Thanks.

Yep.

Mint basicly follows the ubuntu release schedule. Ubuntu releases a new version every 6 months. The versions numbers reflect the date, for example 13.10 was released in 2013 october 10 Every 4th release is an 'LTS' version, with 3+ years of support. They are 10.04LTS (now out of support for all but 'sever' use), 12.04LTS, etc. and 14.04 will be a LTS version when it is released in, you guessed it, april 2014.

Mint 9 was based on 10.04LTS, Mint 13 is basd on 12.04LTS and is the current Mint LTS version, and Mint 17 will be based on 14.04LTS.

The non-LTS releases used to have 18 months support, but from 13.04 on that has dropped to 9 months.

If you dont want to have to reinstall or upgrade every 6 to 10 months, ubuntu users are best off sticking to LTS releases, and Mint users to versions based on ubuntu LTS versions.

I knew about the "new release every ~6 months"...but are you saying all non-LTS releases are killed off as soon as they're no longer that absolute single most recent version? So there's LTS, bleeding-edge, and that's it?

Not quite, there is a few months overlap, but near enough.

You can see the actual support periods here.

One question, though: do you want only Enlightenment, or do you want to choose between desktops? If you only want Enlightenment, you might want to have a look at Bodhi (slightly old and minimal review; sorry), which is a Ubuntu-based enlightenment distribution.