Dolibarr ERP & CRM is a software package to manage small or medium sized companies, freelancers or foundations. We can say Dolibarr is an ERP (Enterprise Resource Planning) or CRM (Customer Relationship Management), or both depending on activated modules.

https://www.dolibarr.org

This is a summary of main Dolibarr features...

Products and services catalog
Stock management
Bank accounts management
Customers, Suppliers or Prospects directory
Contacts directory
Commercial actions management
Orders management with PDF generator
Commercial proposals management with PDF generator
Contracts management
Invoices management with PDF generator
Payments management
Standing orders management
Shipping management
Support NPR VAT (for French DOM-TOM)
Foundations members management
Bookmarks management
Emailing
Agenda
Point of Sale
Donations management
Reporting
Data export tools
LDAP connectivity
A lot of other modules
Multi-user, with several permissions levels for each feature.
Several menu managers (can be used by internal users, as a back-office, or by external users, as a front-office with an other menu and permissions).
Very user friendly and easy to use.
Several skins.
Software is easily customizable and a lot of external addons are also available.