CaseBox is a an open source and PHP/MySQL-powered platform to build a content management system for managing records, tasks and files. It has a desktop-like interface where we can create an unlimited-level of directories and store stuff in the structure preferred.
A user can specify exactly who is able to do what (read/write/delete) with a file/task/action. Attached PDF and DOC files are indexed to offer a fast full text search. Create tasks and deadlines, assign multiple users and track progress.
Separately manage the list of your clients, store custom information (address, phone, civil status and link them to your cases and organizations.