Alternatives to Teamviewer or Anydesk

Rustdesk is an open source alternative.  You can run your own server if you want, or use theirs for free.

DWService.net, is also open source.  They take donations too.  This one gives the remote user admin access to the machine, so more for tech support/MSP use, not so much one you'd setup for users.

Lite Manager is a commercial product, with a pro and free option, and competitive non-subscription pricing. Available for Windows, Android, Linux, etc.

Self-Hosted Mail Servers

Full Suites

Mox

Poste.io

Mail-in-a-Box

Mailcow

Mercury

SMTP Server

Haraka

 

List of interesting projects on Hacker News

Ask HN: What have you created that deserves a second chance on HN?

https://news.ycombinator.com/item?id=34531989

 

Folge to create step-by-step guides of processes

Easily create step-by-step guides and documentation of any process.

https://folge.me/

 

Yark - Youtube archiving made simple

Yark lets you continuously archive all videos and metadata for YouTube channels. You can also view your archive as a seamless offline website

https://github.com/Owez/yark

Use scrcpy to remote display/control your Android device

This application provides display and control of Android devices connected via USB or over TCP/IP. It does not require any root access. 

https://github.com/Genymobile/scrcpy

Corrections Documentary Project

Check out the Corrections Documentary Project organized by Ashley Hunt. The first discusses the impact of private prison industries on public prisons, the war on terror, immigration, and border control. Directly related to these larger forces, the second documentary examines how local communities are often forced into accepting prison building as an economic development project despite evidence that does not support the policies that prisons can revitalize towns and cities.