I'm looking for a web-based open-source blogging platform (like WordPress but with some special specifications) that can provide a timeline-like interface viewable only to logged-in users. I need to deploy it on our company's own server and .Net or PHP is preferred. I'm trying to use this software as a daily employee journaling system, a tool for team update/sync, a way of informing supervisors, archiving previous efforts, and a Knowledge Management tool. It's highly important to me for it to be deployable on-premises and web-based, preferably offering a mobile interface too. I found several platforms but are either cloud-based or proprietary, such as BlogIn.
Do you recommend anything?
Thanks in advance
UPDATE I did some more searching and came across Friendica, Mastodon, Pump.io, Hubzilla, and Diaspora. Friendica seems to be the best choice so far but I'm still indecisive.
Edit
We got a Windows server environment on a bare metal server located in the office, mostly used for .Net applications, and we've recently got a php Cpanel host for our billing and stuff. So as long as we can set it up we're good to go. We also have an Ubuntu server VM but it's not faced to the internet so people won't be able to use stuff hosted on it from outside the company's network, although it's proven itself to be the best environment to setup best available solutions on