Alfresco integrates with ONLYOFFICE to enable document creation, editing, sharing and collaboration online in your browser. You can install it on premise. Here is the contact information for personel located in Dallas, Tx who can answer question about pricing, licensing and support. The free ONLYOFFICE editor that you can activate with Alfresco comes with only 20 document connections. It is enough to test it, but not enough to use commercially, and it does not come with support. To get the support and more document connections you need to purchased a commercial license from ONLYOFFICE U.S. The first level of support is currently also in the U.S. Here is the contact information for you.
sales_us@onlyoffice.com ph. 972-544-6877
If you need help installing ONLYOFFICE editors with Alfresco these guys can help you with that as well.