There are relatively few truly open source ERP systems that are on the market. The 2-3 among them are OfBix (maintained by Apache Foundation), Adempiere derivatives (with no home) & ERPNext maintained by ERPNext foundation & Frappe.
ERPNext + Frappe Framework can do many things out of the box including act as a static site generator. In fact the entire documentation is published using GitHub repository + Frappe Application generating the content.
Is it a static site generator?
If you are asking whether it is a Static Site Generator (SSG), the simple answer is a pointer to their documentation website https://docs.erpnext.com
A beautiful example of site created using ERPNext / Frappe Framework
The documentation of ERPNext has markdown files and images & is combined and generated by a FRAPPE application.
Find the source on Github
The GitHub link to their website with the underlying site generator can be found here : https://github.com/frappe/erpnext_documentation