Anyone can use AGOL, if you go to ArcGIS.com, click the Sign In button, and if you do not already have an ESRI global account, just create one, it is free. And much of AGOL is free, too, though it is not immediately apparent.
You can make simple maps online, using their data or services from other free sources, publish and share them. There are some examples you can see at the site.
The UW-Madison has an Organizational Account on AGOL. There are a limited number of logins and credits available for this. Also included in our Subscription are access to the Business Analyst Online and the Community Analyst, as well as some premium services like the Landscape Analyst layers. If you would like to participate, contact the site administrator for access options and an invitation with the form below.
Please use your UW email address.