What are the programs for the structured storage of electronic documents of the enterprise?

Question

Document flow

There is a small business. The volume of documents on it is gradually growing. First, everything was done with tags in e-mail, then a bunch of nested folders on disk. I understand that now something more convenient is needed.
We are talking about instructions, orders, scanned contracts, additional agreements, any documentation from contractors, your plans, technical specifications, calculations - in general, everything that can be stored in files.
You need a program or service for convenient cataloging (and so that one file can belong to 1 or several directories) and sharing access.
Advise, please, from free.

Answer 1

convenient and free NO
choose from:
https://fosslook.com/
https://www.alfresco.com/
well, 1C, where without it,
everything else DMS is even more expensive to implement
, you can simply store it in the network version of some https://www.essentialpim.com/

Answer 2

I wrote a program for organizing documents (SD) for myself with the creation of categories, folders and documents in the form of a tree structure, if necessary, you can specify your own status, date of the document and a description for it. Two files can be attached to each document or folder. It is possible to block the first document from accidental/intentional deletion. You can also create multiple links to other documents, descriptions and flags for important documents. All files are opened by standard programs by double clicking. There is a search by the name or number of the document (you can use the mask). See who, when and what data was changed/deleted. To download information, you can specify one file per windows or a whole directory. Yes, you can set a password to enter ... For individual use, it is absolutely free.www.santig.ru/data/documents/SD.zip