AIDE (Advanced Intrusion Detection Environment) is a file and directory integrity checker. It creates a database from the regular expression rules that it finds from the config file. Once this database is initialized it can be used to verify the integrity of the files. Several message digest algorithms are used. All of the usual file attributes can also be checked for inconsistencies.
EtherApe is a GNOME/pcap-based etherman, interman, and "tcpman" clone. It displays network activity graphically. Active hosts are shown as circles of varying size, and traffic among them is shown as lines of varying width. It supports Ethernet, FDDI, Token Ring, ISDN, PPP, WLAN, and SLIP transports. It knows about VLANs, IP, IPv6, TCP, UDP, FTP, and a number of other protocols. Additional statistics windows will let you concentrate on protocols or nodes.
di is a disk information utility that displays everything that df does and more. It features the ability to display your disk usage in whatever format you prefer. It also checks the user and group quotas, so that the user sees the space available for their use, not the system wide disk space. It is designed to be highly portable across many platforms and is great for heterogenous networks.
CensorNet Professional is a Web filtering and Internet management tool that is designed to protect, control, and monitor individuals accessing Internet resources on a local area network. It features the ability to control users and machines, group policies, time quotas, realtime content filters (by file extension or image/MIME type), modules, comprehensive reporting with audit trails and management reports, access schedules, and bandwidth limitations. Transparent authentication with Active Directory is available for ease of deployment. Administration can been done using a Web interface.
Oak monitors syslogs from a collection of servers, and notifies the operators when problems arise. In addition to providing immediate notification of critical issues, it will also batch less critical problems into summary messages, which can be sent less often, and via any medium. It is part of the 'ktools' collection of network administration utilities.
Passwd_exp notifies users via email of upcoming password or account expiration. Its simple modular architecture allows you to perform expiration checks on any data source you use (SQL databases, LDAP...), send expiration warnings only to desired users or group and on selected days only. Administrators can use it to review expired accounts in the system. Support for Linux and Solaris shadow (including LDAP and NIS systems) and BSD passwd systems is included.