Likewise is the creator of Likewise Open, an open-source program that lets Linux and Mac users authenticate against and join Active Directory domains and forests. Likewise Open also enforces AD (Active Directory) password policies across Linux systems.
You don't have to take their word for it. I've been using Likewise for years, and it works quite well. Now, Ubuntu is going to be including the latest version of Likewise Open 5.4, in the next edition of Ubuntu, Lucid Lynx.
I like this plan a lot. While I've not always been happy with LikeWise--I'm still not crazy about their competing with Samba with their own CIFS (Common Internet File System) server--Likewise does do a really nice job with AD integration for Linux.
So, if you've been pondering including Ubuntu Linux desktops in your Windows network, start playing with Lucid Lynx and LikeWise Open. If you like what you see, and I think you will, you might start planning on deploying them sometime in 2010.
Likewise Enterprise essentially makes your Linux and Mac boxes into full-fledged members of your AD domain. That is to say you can use group policies to manage them, enable SSO (Single Sign-on) for applications and import directories. In addition, you can manage and audit AD from your Linux box with Likewise Enterprise.
All in all, I've found it over the years to be an impressively network management package, and I'm really look forward to seeing how it all comes together in April when the full Lucid Lynx distribution goes into production.