What self-hosted help desk would work well for a 2,000-user air-gapped environment?

Request Tracker is mature, flexible, and very email-oriented. It runs well on Linux and can handle a large number of queues and workflows, but administration is less point-and-click than newer products; deeper customization may require comfort with the underlying configuration and Perl code. For a simpler system, osTicket or FreeScout can work, though I’d evaluate their scalability and feature depth carefully for 2,000 users.

ManageEngine ServiceDesk Plus has worked well for several organizations and is more polished and powerful than many lightweight open-source tools. It may be a good fit if you want structured workflows, reporting, inventory, and vendor support. Make sure the exact self-hosted licensing and offline activation process meet your environment’s requirements.

GLPI is a very capable option, especially if asset and configuration management matter as much as ticketing. It can do considerably more than a basic help desk, but plan carefully for administration and offline patching. In an air-gapped environment, maintaining PHP, database, and application dependencies can be more work than the initial installation.

Zammad is probably one of the strongest modern choices. It has a much friendlier interface than older help desk products, supports email-created tickets, and can be deployed with containers. YouTrack is also worth considering if you want something closer to a Jira-style issue tracker, although it may be more platform than you need for a traditional service desk.

The air-gapped requirement should drive the evaluation more than the interface. Ask every vendor how offline licensing, upgrades, dependency updates, backups, and security patches work before choosing. Container-based deployment can simplify repeatable updates, but you still need a documented process for importing and validating images. I’d define your pain points and success metrics first, then run a proof of concept with a few support teams before committing.