Freshservice - Freshservice: the one-stop cloud solution for all your IT management needs.
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.
Request Tracker - open-source enterprise grade issue and ticket tracking system
Snipe-IT - Managing assets with a Google doc or a shared Excel spreadsheet is more common than you think.
NetHelpDesk - Leading provider of help desk software and customer support software. Trusted by IT professionals and service desks for over 20 years.
Zabbix - Track, record, alert and visualize performance and availability of IT resources