Short answer:
There is no difference. Alestic.com simply lists the same Ubuntu AMIs as ubuntu.com, and those AMIs are published by Canonical, not by me.
Long answer:
I publish the web site http://Alestic.com
I used to publish unofficial Ubuntu AMIs under the name "alestic", primarily in 2007-2009 (Ubuntu ). I worked with Canonical to transfer this work to them and now Canonical has paid employees who publish official Ubuntu AMIs. Canonical builds the AMIs for Ubuntu 10.04 LTS Hardy through the present (Ubuntu 11.10) and into the future.
Since a lot of people came to the Alestic.com web site to find out what the latest Ubuntu AMIs were, I continue listing the ids of the Ubuntu AMIs from Caninical in the table at the top of the web site. I clearly identify which AMIs are published by "Canonical" (almost all of them today) but the myth that I publish all of them keeps reappearing from time to time.
I'm looking at changes to wording and layout on the site to better communicate the truth, while continuing to provide the service of listing the AMIs.
Note: There is one series of active Ubuntu server AMIs that I still publish under the name "alestic". Canonical publishes an instance-store AMI for Ubuntu 8.04 LTS Hardy, but no EBS boot AMI. I copy the image published by Canonical (exactly, no changes) and publish an EBS boot AMI for Ubuntu 8.04 LTS Hardy. There are a few companies that depend on this, but it is not recommended if you are just getting started.
Note2: I occasionally publish public AMIs for specific tasks/configurations. For example, I have been experimenting with public AMIs for running a Git server with gitolite: http://alestic.com/alestic-git/
Note3: I create custom AMIs for various companies, but most of these are private.
Alright, so the issue was definitely on the Ubuntu side, but I figured it all out.
You can use this to enable an IP address alias on the primary network interface that allows you to use two IP addresses on a single nic (ens3 is the network interface, usually called eth0 but for some reason the AWS device is called this instead)
ip address add 172.31.0.0/24 dev ens3
And then if you want to keep those settings on reboot, you'll need to add the following to nano /etc/network/interfaces
auto ens3:1
iface ens3:1 inet static
address 172.31.0.0 #your secondary private IP
gateway 172.31.48.1 #your gateway, get with `ip route`, after "default via "
netmask 255.255.240.0 #get the "Mask" with `ipconfig` from your nic
And reboot and you should be all good to go!
Best Answer
They are kind of released.
If you look at: https://cloud-images.ubuntu.com/query/xenial/server/released.current.txt you will find the AMI id's.
As of right now though, they are not public, atleast not in eu-west-1. Most likely Amazon is vetting them, because they'll become official images.