ZMANDA maintains and supports the freely available AMANDA, as well as ZMANDA Recovery Manager for MySQL. It also provides network and cloud backup services that it sells commercially.
Essential open source Windows admin tool No. 3: MailArchiva
Email archiving is front and center in Exchange 2010, thanks to the increase in compliance regulation enforcement across the industry. But for those who are not yet using Exchange 2010, MailArchiva provides a worthwhile means for bringing compliance to Exchange 2000/2003 and other mail servers, such as Postfix, Sendmail, Qmail, iMail, and Lotus Notes.
MailArchiva comes in both an open source and an enterprise flavor. To see a list of features and how the two editions vary, browse the MailArchiva site.
Essential open source Windows admin tool No. 4: Exchange 2010 RBAC Manager
Exchange 2010 RBAC Manager is a great tool for admins working with role-based access control and Exchange. RBAC Manager (aka RBAC Editor GUI) helps overcome the lack of a GUI tool to work with the new role-based administration side to Exchange, enabling admins to connect, whether or not you're a PowerShell master. The tool is written in C# and uses PowerShell behind the scenes to allow you to create and manage roles in your Exchange 2010 environment.
Essential open source Windows admin tool No. 5: Core Configurator 2.0 for Server Core
Offering a command-line version of Windows Server 2008 and Windows Server 2008 R2 at installation was a great idea. With its light footprint, it allows a small attack surface as well. The only problem? It required administrators to crack open command-line books to configure their servers. This free tool provides a GUI method for managing tasks.
Essential open source Windows admin tool No. 6: AutoSPInstaller for SharePoint 2010
Anyone who has ever installed SharePoint knows that the SQL databases created are a mess in terms of naming, resulting in large GUID databases titles that are completely inconsistent. In contrast, AutoSPInstaller utilizes a variety of scripts to install SharePoint and makes sure database names remain clean in the process.
Essential open source Windows admin tool No. 7: OCS Inventory