Igloo is an intranet you'll actually like: built with easy-to-use,
integrated apps like shared calendars, Twitter-like microblogs, file
sharing, and more. Everything you need is built-in, and everything is
social. This means if you upload a file or write a corporate blog post,
your employees can share it, comment on it, rate it, like it, and even
manage versions.
The idea is to get your whole company communicating better.
If your company has a legacy intranet or a customer community built on
SharePoint, you should give Igloo a try. This report from
Igloo outlines the five main areas SharePoint falls short and how Igloo does it better.