OTRS is an Open source Ticket Request System (also well known as trouble Ticket System) with many features to manage customer telephone calls and e-mails. The system is built to allow your support, sales, pre-sales, billing, internal IT, HELPDESK, etc. department to react quickly to inbound inquiries. Do you receive many e-mails and want to answer them with a team of agents? You're going to LOVE the OTRS!
OTRS::ITSM is the first ITIL compliant and Open Source IT service management solution.