A most powerful software for sharing documents.
Expression Engine is not that well know outside the web industry but one of the best CMS softwares for building more demanding web sites that required advanced functionality. IT takes a little longer for web experts to set up but once it’s all done it’s extremely fast, handles SEO well gives the designers a blank canvas to create what is required.
Clients also find it easy and intuitive to use with a logical backend that can be customised to whatever the client requires. Like WordPress CMS it does require a lot of extensions (plugins) to be added to increase its capability and although most do require a paid licence they are not expensive and quite often very powerful.
If the developers build custom extensions they do integrate without the client even knowing they are bespoke and add anything that is required and maybe not available otherwise.
To summarize, if the system requires very specific functions and settings Expression Engine CMS is well worth consideration. You will though like most CMS’s require a specialist to set it up.