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.
NetXMS is a network monitoring and management system with a modular architecture. It can be used for monitoring an entire IT infrastructure, starting with SNMP-capable hardware (like switches and routers) and ending with applications on servers. The system has a three-tier architecture; the information is collected by monitoring agents (either its own agents or SNMP agents) and delivered to the monitoring server for processing and storing, where it can be accessed by using the management console. It features centralized configuration and centralized agent upgrades.
Nagstamon is a Nagios status monitor with a UI that resides in the systray or as a floating statusbar on your desktop. It informs you in realtime about the status of your Nagios, Icinga, Opsview, Ninja, Check_MK/Multisite, Centreon, or Thruk-monitored network. It alerts you with sound and visual notification. Failed hosts and services are easy to connect with by SSH, RDP, and VNC. Custom actions can be run on certain events. It works best with GNOME, but also with KDE, Mac OS X, and Windows.
The stunnel program is designed to work as an SSL encryption wrapper between remote client and local (inetd-startable) or remote server. It can be used to add SSL functionality to commonly used inetd daemons like POP2, POP3, and IMAP servers without any changes in the programs' code. It will negotiate an SSL connection using the OpenSSL or SSLeay libraries. It calls the underlying crypto libraries, so stunnel supports whatever cryptographic algorithms you compiled into your crypto package.
Zenoss is an enterprise network/systems management application that provides an integrated software package for monitoring availability, performance, events, and configuration across layers (network, servers, applications, environment, etc.) and across platforms (Linux, Windows, Unix, etc.).
PowerBroker Identity Services is an application that joins Linux, Unix, and Mac OS machines to Microsoft Active Directory and securely authenticates users with their domain credentials. Features include: joining non-Windows systems to Active Directory domains in a single step from the command line or from a GUI; authenticating users with a single user name and password; enforcing the same password policies for all platforms; supporting multiple forests with one-way and two-way cross forest trusts; caching credentials in case your domain controller goes down; and providing single sign-on for SSH and Putty. It does not require Active Directory schema changes for installation.
Inguma is a penetration testing and vulnerability research toolkit. The framework includes modules that discover hosts, gather information, fuzz targets, brute force user names and passwords and attempt exploits. While the current exploitation capabilities are limited, the program provides numerous tools for information gathering and target auditing.