OCS Inventory is also able to detect all active devices on your network, such as switch, router, network printer and unattended devices. OCS Inventory NG includes package deployment feature on client computers. From the central management server, you can upload packages which will be downloaded through HTTP/HTTPS and launched by agent on client computer.
OCS Inventory is released under the GNU General Public License, version 2.0 (GNU GPLv2). The GNU GPL provides for a person or persons to distribute OCS Inventory for a fee, but not actually charging for the software itself, because OCS Inventory is free.
Read more and download the tool from here - http://www.ocsinventory-ng.org/en/