OpenCATS

Mature open-source ATS for staffing agencies and HR departments

Open Source

OpenCATS is one of the most mature open-source Applicant Tracking Systems available. Originally designed for the staffing industry, it has evolved into a robust solution for both internal HR departments and recruitment agencies. It is a stable, "classic" web application that provides deep functionality for managing large candidate databases.

License: GPL-3.0
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Features

Core Features

  • Candidate Database - Centralized storage for all candidate data, including resumes, notes, and activity history
  • Resume Parsing - Automatically extracts contact details and skills from uploaded resumes (PDF/Word)
  • Pipelines & Workflows - Configurable status pipelines to track candidates through the hiring process
  • Full-Text Search - Powerful search across resume contents and candidate tags
  • Calendar Module - Built-in calendar for scheduling interviews and setting follow-up reminders
  • Job Publishing - Tools to publish job openings to an internal career portal or external XML feeds
  • Reporting - Basic reporting on activity logs, placements, and pipeline health

Target Audience

  • Staffing Agencies
  • Small to Mid-sized businesses with technical IT support
  • Organizations requiring full data sovereignty

Deployment

Type: Self-Hosted

Requirements:

  • Linux server
  • Apache or Nginx
  • MySQL or MariaDB
  • PHP 7.0+

Advantages

  • +Completely free with no vendor lock-in
  • +Highly stable and mature codebase
  • +Vast community knowledge base
  • +Full control over data and customization

Limitations

  • UI is dated (Web 2.0 style)
  • Requires self-maintenance (security patches, backups)
  • Mobile experience is limited
  • Steeper learning curve for non-technical users

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WP Job Manager is a lightweight WordPress plugin that transforms any WordPress site into a job board with basic applicant tracking capabilities. It is ideal for organizations already using WordPress who need simple job posting and application management without a full-featured ATS.

Key Features:

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OrangeHRM

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OrangeHRM is one of the most widely-used open-source HR management systems globally. While primarily an HRIS, it includes a recruitment module that handles job postings, candidate tracking, and interview management as part of a comprehensive HR suite.

Key Features:

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Flowxtra

Cloud-based ATS with unlimited free job postings

SaaS

Flowxtra is a cloud-based Applicant Tracking System (ATS) and talent management platform designed to eliminate the technical complexity of self-hosted recruiting software. It operates on a freemium model, offering unlimited job postings even on the free tier, with paid plans unlocking advanced features like multi-office management, analytics, and employee onboarding. The platform emphasizes ease of use and immediate deployment—users can start recruiting within minutes without server setup, database configuration, or ongoing maintenance.

Key Features:

  • Unlimited Job Postings
  • Multiposting
  • CV Parsing

Last updated: 2026