I'm running a Nextcloud server (v13.x...still need to migrate it to v15, although v13 still gets updated) on a old Linux box. Until this point, I must say that it is a very good experience. Has a lot of features in and off itself, but can be expanded with 3rd party mods. In my setup hardly any mods have been added, I mainly use it to transfer files to it from another continent by script using CarotDAV.
For my intends and purposes it is such a good solution that I didn't bother looking at anything else anymore.
However, if you look for something less resource intensive, WebDAV is pretty simple and you could simply enable the WebDAV mod from the Apache web server software. And I'm sure it is a pretty standard feature on the other main web server software packages (IIS, NGinX). That is the most basic version of a web drive you will ever get. but not really recommended if security is of any concern. Nextcloud comes with already with pretty decent authorization options and offers more options for extra security if you so desire.