GroupOffice is a groupware suite that takes your office online, implementing online collaboration and CRM. It allows you to share projects, calendars, files and email online with co-workers and clients. It is easy to use and fully customizable. It also features synchronization with PDAs and Outlook.
Distributed Checksum Clearinghouse (DCC) is a system of clients and servers that collect and count checksums related to mail messages. The counts can be used by SMTP servers and mail user agents to detect and reject bulk mail. DCC servers can exchange common checksums. The checksums include values that are "fuzzy", or constant across common variations in bulk messages.
The GNU Gatekeeper is a free H.323 gatekeeper based on the OpenH323 project. You can use it to manage a Voice-over-IP network and let endpoints (e.g., Netmeeting) communicate through symbolic names. It also has an external interface for billing and other applications. It runs on a number of Unix versions (including Linux and Solaris) and Windows.
Bugzero is a Web-based change management and issue tracking system used in a distributed team environment to track software bugs, hardware defects, test cases, or any other issues. It can also be used equally well as a helpdesk customer support, trouble ticketing, or email management system to collect and manage customer feedbacks, incidents, requests, and issues. It is easy to use, but still flexible and adaptive, and can be configured to fit to your organization's unique business process and workflow.