Flmngr - Free PHP File Manager
draw.io - Online diagramming application
Responsive Filemanager - RESPONSIVE FileManager is a free open-source filemanager image manager stand-alone and plugin for TinyMCE 4, CKEditor and CLEditor. It's possible to select files, images and videos from a server folder and upload them from your computer
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
CKFinder - CKFinder is a powerful and easy to use Ajax file manager for web browsers.
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.