Odoo is a suite of web based open source business apps.
It's main apps include an <ahref="https://www.odoo.com/page/crm">Open Source CRM</a>, <ahref="https://www.odoo.com/page/website-builder">Website Builder</a>, <ahref="https://www.odoo.com/page/e-commerce">eCommerce</a>, <ahref="https://www.odoo.com/page/project-management">Project Management</a>, <ahref="https://www.odoo.com/page/accounting">Billing & Accounting</a>, <ahref="https://www.odoo.com/page/point-of-sale">Point of Sale</a>, <ahref="https://www.odoo.com/page/employees">Human Resources</a>, Marketing, Manufacturing, Purchase Management, ...
It's main apps include an <ahref="https://www.odoo.com/page/crm">Open Source CRM</a>, <ahref="https://www.odoo.com/page/website-builder">Website Builder</a>, <ahref="https://www.odoo.com/page/e-commerce">eCommerce</a>, <ahref="https://www.odoo.com/page/project-management">Project Management</a>, <ahref="https://www.odoo.com/page/accounting">Billing & Accounting</a>, <ahref="https://www.odoo.com/page/point-of-sale">Point of Sale</a>, <ahref="https://www.odoo.com/page/employees">Human Resources</a>, Marketing, Manufacturing, Purchase Management, ... Each application is standalone but you get a full featured <ahref="https://www.odoo.com">Open Source ERP</a> if you install several apps as they integrate to each others.