License and cost mhd is released under the GPL license. This basically means you can grab it, do with it whatever you wish as long as you recognize the original developer of the software. It would be great if you enjoy using mhd and could submit patches to me for this development version. Support tickets is what the whole thing is about. Users are the tech personell answering support tickets.
Clients are the people submitting tickets.
A TID is a document detailing procedures to solve a certain technical issue. You can add solutions to a knowledgebase and the users can see the list of added solutions. You can customize the message in the mails send for each new ticket or event. The client can submit tickets without being logged in through the start page. The client can book equipment without being logged in through the start page.