OTRS - Open Source Helpdesk-Ticketing system (OnPremise/SaaS model)
OTRS (Open Ticket Request-source System) is one of the best open-source helpdesk systems today. Its features are beyond the commercial competitive products of this kind. OTRS is very robust; proposed to control a large number of customer inquiries (more than a thousand a day). Its features include an automatic response to the client, auto-assignment of problem investigator, automatic ticket numbering, reporting and statistics, and other modules such as ITIL-ITSM (IT Service Management, Information Technology Infrastructure Library).