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.
MIB Smithy SDK is a dynamic extension to Tcl/Tk (8.4+) that allows development of custom scripts for controlling SNMP agents, manipulating SMI definitions, doing conversions, and more. It is based on the core of Muonics' MIB Smithy, and the SDK supports SMIv1 and SMIv2, as well as SNMPv1/v2c/v3 with HMAC-SHA-96 and HMAC-MD5-96 authentication and DES/CBC and AES128/CFB privacy. It also provides complete read-write access to all elements of SMI/MIB Module definitions, unlike similar extensions that provide only read access to a limited subset. The SDK allows multiple discrete SMI databases and SNMP sessions, and provides all of the built-in validation and error recovery capabilites of the full product, without the visual MIB development environment.
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.
Rogue Detect sends DHCPDISCOVER packets to the network and listens for DHCP servers to respond. It can run continuously as a daemon, or do a single probe and quit. It's written in Perl and can be easily extended to take any action you can think of in response to an unknown DHCP server (send pages, disable them, etc).
nexB OpenAssets is a tool for inventorying, managing, and monitoring applications, software, hardware, networks, and generally any IT asset. It is designed so that system administrators, IT, and finance can determine what they have, how it is configured, what it is used for, and how much it is being used, so that informed decisions can be made. It complements existing network management software, integrates with a growing number of protocols and tools, and features no-agent discovery and inventory, configuration management including dependencies and correlation, monitoring, and reporting. It makes extensive and innovative use of XML, Xpath, and Xquery.
OpenSMART is a monitoring (and reporting) environment for servers and applications in a network. Its main features are a nice Web front end, monitored servers requiring only a Perl installation, XML configuration, and good documentation. It is easy to write more checks. Supported platforms are Linux, HP/UX, Solaris, AIX, *BSD, and Windows (only as a client).