GnuCash - A personal and small-business financial-accounting software, licensed under GNU/GPL and available for Linux, Windows, Mac OS X, BSD, and Solaris.
Pilot - Focus on your business, knowing that our expert bookkeepers, aided by software superpowers, are taking care of your books.
Synder - AR Automation
Xero - Xero is online accounting for your small business.
Gusto - Gusto. Payroll, benefits and compliance in one integrated product. We're here to change how the world works, and put people first.
FreshBooks - The ideal accounting software for small business owners.