osFinancials

LedgerSMB is an open-source web-based double-entry accounting system featuring quotation, ordering, invoicing, projects, timecards, inventory management, shipping, and more.

FrontAccounting (FA) is a professional web-based and self-hosted accounting system for the entire ERP chain written in PHP, using MySQL. FA is multilingual and multi-currency.

Momenteo is a cloud-based accounting solution designed for freelancers in various industries. Key features include invoice and estimate creation, expense and time tracking, client management, and financial reporting.

GnuCash is a personal and small-business financial reporting and accounting solution that helps track bank accounts, stocks, income, and expenses.

Wave is an online accounting platform exclusively designed for small business owners, freelancers, and consultants.