We've used iDempiere for almost a decade, but used it as an inventory maintenance and quoting system, as we used Openbravo (its now gone cousin) as our primary ERP.
Since last year we've been using iDempiere to manage all our accounting, this is truly an enterprise system and I cannot understand how people don't use it and regard it as the best (maybe because its written in Java and that pretty heavy and difficult to maintain).
The system and structure is very similar to Openbravo but has some key differences on how it handles the input of some key accounting ledgers (for example how to input expenses, how to add payments to the invoices etc), furthermore reporting is not that straight forward.
On 2023 I plan to go in depth with this system, become an expert and put out a lot of content, including step by step videos no youtube, so the this jewel of a system can be used by every small business in the world. additionally hope to bump up the community as it should be much greater and active than what it is at the moment.
Note: iDempiere is free and opensource.