I've been trawling the net trying to find a good (open source and PHP based) file manager, where I can allocate file/directory access to specific users. The purpose of it is for an internal office app, where employees have dedicated private areas containing confidential docs like appraisals etc. The CMSes I've looked at so far fall just short of this amount of fine grained access control, although an earlier version of Drupal had a module which did precisely this, but is no longer supported. Does anyone here know of something like this? Thanks for any tips
Mollify doesn't yet come with integration into CMSes, but it seems to meet all of the criteria you stated.
It's under the EPL 1.0 license with the option to buy a commercial license if that's not good enough. (I contacted the author and confirmed that interpretation of the website copy is correct.)
Also, Mollify 2 (currently in alpha) uses the GPL 2.0 for better compatibility.