"Open-Source" is a bit of a misnomer. The majority of the important modules are enterprise only. That said even enterprise is source-available for paying customers which is a breath of fresh air compared to the competition.

Regarding the strong fundamentals: - A clever, extremely flexible, roles/permissions system. It is based on giving CRUD permissions to user roles, allowing to define access rules based on the fields (for instance a READ access with a record rule [('user_id', '=', user.id)] would allow to read only own records). In most of the software permissions are expressed in the code, in Odoo they are abstracted and enforced at ORM level. - The custom ORM system is very strong and allows to create objects and fields at runtime. You can create a model and its fields and start using it right away without restarting the server.

Some of the smaller bright ideas: - Records navigation is rather smart: the pagination system allows to manually define the records range to be seen avoiding the usual "records per page" dropdown; standard filters can be defined using the same domain syntax from access rules above (the filter for "My records" would be [('user_id', '=', user.id)]). - Many views use kanban, I find them extremely practical to get a good overview, in particular for CRM opportunities and candidates screening processes.

ERPNext on the other hand is fairly mature and fully open source: https://frappe.io/erpnext

They are running a massive out-of-home media campaign in my city, they billboard even busstops in home-districts with lowered traffic speed in the suburbs :-))

Their API documentation is virtually nonexistent. You have to basically reverse engineer their poorly documented models to get anything done, and those can change between releases. I suspect they deliberately under-document their changes in order to force people to pay them more money. At least I hope their official partners get access to better documentation.

Beware putting all of your eggs into this particular basket.

2019 Story of Odoo: Open-Sourced Competitor to Oracle, SAP (195 points, 74 comments) https://news.ycombinator.com/item?id=21865699

2014 Odoo: The new OpenERP (44 points, 44 comments) https://news.ycombinator.com/item?id=7750020

Nice to see them here! I played a bit with customizing V7. Was a pretty unique experience to see how it works internally

Everything could be changed. Which is basically an advantage and a disadvantage. Please try to adjust to the system if possible :)

In my experience, the Enterprise version is poor value: support is often absent or slow, and most of the “Enterprise-only” features are not magical—they can be developed or replaced with custom modules at a lower total cost if you know what you’re doing.

Odoo’s real strength is the unified data model and extensible core. If you control your stack and invest in competent development instead of licenses, Community can be a solid ERP foundation. If you expect a polished SaaS with strong vendor support, Enterprise will likely disappoint relative to its price.

Been through the source code, interesting ideas in it.