RackTables - Racktables is a nifty and robust solution for datacenter and server room asset management.
GLPI - GLPI is the Information Resource-Manager with an additional Administration- Interface.
DCImanager - DCImanager is a platform for managing physical equipment. Connect any physical equipment to a single platform. Use the platform to manage your servers, switches, PDU as well as physical and virtual networks.
Lansweeper - Lansweeper discovers Windows, Linux and Mac machines in your network.
NetBox - NetBox is an open source web application designed to help manage and document computer networks. NetBox was developed specifically to address the needs of network and infrastructure engineers.
FusionInventory - Fork of the OCS Inventory project that enables users to inventory their IT assets.