osTicket
With nearly 3,900 GitHub stars, over 1,800 forks, and continuous development since 2013 culminating in the v1.18.4 release in June 2026, osTicket remains one of the most deployed open-source help desk systems worldwide, trusted by organizations from small businesses to universities and government agencies. The PHP backend on Apache or IIS with MySQL stores every ticket, response, and attachment while the web interface provides separate agent and customer portal views with role-based access control across departments, teams, and individual agents. Customers submit tickets through web forms, email piping, or phone-entry by agents, and configurable ticket filters automatically route incoming requests to the correct department, assign agents or teams, set priority levels, apply SLA plans, and trigger canned responses based on matching criteria including custom field values. Agent collision avoidance locks tickets during response composition to prevent duplicate replies, while SLA plans with business hour schedules track due dates and escalate overdue tickets automatically. Custom forms and fields let organizations capture structured data specific to each help topic — from IT asset tags to billing account numbers — with configurable required and internal-only visibility. The advanced search system with saved queries and CSV export enables reporting across all ticket metadata and custom fields. The customer portal provides ticket tracking, profile management, and knowledge base access. OAuth2 plugin support enables modern email authentication with Microsoft 365 and Google. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-2.0 licensed.
GLPI
GLPI combines helpdesk ticketing, hardware inventory, license compliance, CMDB, and project management in a single PHP application with over 6,200 GitHub stars and 500,000+ Docker pulls, offering a unified ITSM platform that replaces ServiceNow, Freshservice, and ManageEngine without per-agent pricing. The ITIL-aligned service desk handles incidents, problems, changes, and service requests with configurable SLA management, approval workflows, satisfaction surveys, and business rules that automate ticket routing, escalation, and categorization. Native dynamic inventory through the GLPI Agent discovers Windows, Linux, and macOS endpoints with deep hardware profiling, while network discovery scans switches, printers, and infrastructure devices automatically. Software and license management tracks per-user and per-core license allocations with compliance reporting, expiration alerts, and financial cost tracking across the asset lifecycle from purchase through depreciation to disposal. Data center infrastructure management provides rack visualization with U-level positioning, PDU tracking, and connection mapping. The integrated forms editor builds custom request portals for end-users, while the self-service portal lets users submit tickets, browse the service catalog, and reserve assets. Webhooks trigger external HTTP calls on events, and the High-Level REST API v2 exposes every resource for automation. A plugin marketplace offers 90+ extensions for monitoring integration, advanced reporting, and authentication. Deploy via Docker with the glpi/glpi image alongside MySQL. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPLv3 licensed.
Peppermint
A deliberately simple ticketing system standing in for both Zendesk and Jira: Peppermint handles internal staff requests and external customer support alike. The stack is modern full-stack TypeScript: Next.js and React over Prisma and PostgreSQL, which makes it light to run and approachable for developers extending it. Ticket creation is straightforward - a markdown editor with file uploads, assignment, status tracking, and a logical workflow that new agents grasp without a manual. Mailbox integration converts email into tickets automatically: configure SMTP/IMAP per mailbox and incoming messages become trackable tickets. Each client accumulates an interaction history, giving agents context on every past request before replying. Two touches distinguish it from bare-bones ticketing: a built-in markdown notebook with todo lists for internal documentation and knowledge sharing, and OIDC authentication so agents sign in through your existing identity provider - Keycloak, Okta, Authentik, or Azure AD. Configurable webhooks and email notifications push ticket events to third-party services. The UI is responsive from mobile to 4K, and everything works fully offline in air-gapped environments. Docker-native and scalable via Kubernetes, with an active community of 3,000+ GitHub stargazers.