[Blind-sysadmins] Ticket Systems like osTicket and OTRS

Hi all, At the moment I am looking for a new ticket system. Currently we are using a very old version of osTicket because of some accessibility issues. Which ticket system are you using in your daily work? And how accessible is it with screen readers? Is it free/open source? If not how much does it cost? Greetings and thanks to all who can write in, Simon