Open Source Payroll Software
Payroll is the one back-office system that is wrong in public: a miscalculated tax withholding or a late filing becomes an employee's problem and a regulator's penalty in the same pay cycle, and the rules change by jurisdiction every year. The open source payroll software here keeps the calculation engine, tax tables, and pay-run logic open and self-hosted, so you can see exactly how gross becomes net, adapt it to local rules, and keep salary data - some of the most sensitive records you hold - off a third party's servers.
Frappe HR
Open source HR and payroll software for employee lifecycle, leave, attendance, and payroll management
Horilla
Open source HRMS for recruitment, attendance, leave, payroll, and employee management
OrangeHRM
Free, open source HR management system covering the essential HRM functions for any organization
NotrinosERP
Web-based open source ERP for accounting, CRM, inventory, manufacturing, payroll, and approvals
OCA Payroll
Odoo payroll modules for employee payroll records, accounting, and contract advantages
Payroll Engine
Open-source, regulation-driven framework for building payroll applications