SNMP

FreshTomato firmware project is a system based on Linux, dedicated for routers with Broadcom chipset and distributed on the GPL license. This advanced system consists of a particularly friendly interface, thanks to which even inexperienced users can easily work with it.

Fork of the OCS Inventory project that enables users to inventory their IT assets.

Observium is an autodiscovering PHP/MySQL/SNMP based network monitoring which includes support for a wide range of network hardware and operating systems including Cisco, Linux, FreeBSD, Juniper, Brocade, Foundry, HP and many more.

10 years mature OCS Inventory NG, an OpenSource computer inventory and package deployment system for Win32 and Unix and Apple and Linux. Works with glpi-project.org helpdesk.

SnmpB is an SNMP MIB browser written in QT. It supports SNMPv1, SNMPv2c & SNMPv3. SnmpB can browse/edit/load/add MIB files and can query SNMP agents. It also supports agent discovery, trap events, and graph plotting.