Node-RED
NodeRED.org - homepage for the drag-and-drop control and monitoring software project.
Getting started with Node-RED - tutorials and learning.
Home Automation
Home Assistant - home automation software.
Home Assistant Control Panel - simple control panel for your Home Assistant build. Can be set up in browser or run locally on your HA instance. A nice alternative if you're not happy with the base HA panel.
Beginner's Guide to Home Assistant - a useful Youtube video on getting your Home Assistant environment set up.
Big List of Useful Home Automation Nodes - a list of Node-RED automation nodes that work with Home Assistant.
openHAB - home automation software.
OpenMotics - home automation with hardware and software solutions.
WebRTC
WebRTC.org - oepn API project for online video, audio, and chat collaboration.
Ivy Software Bus
Ivy - a way to distribute information via text messages.
Experimental Physics and Industrial Control System
EPICS - infrastructure for building distributed control networks, used in particle accelerators and telescopes.
Chicago Brick
Google Chicago Video Wall Software - created by Google employees to manage content for the multi-display video wall in the Chicago office lobby, supporting both video and coded visual elements.
p5.js - a software sketchbook that allows creation of visual elements in a browser. Ships with Chicago Brick.
Promys
Promys.me - a local wireless screen sharing project for Raspberry Pi. Rudimentary, but a good idea.
VideoLAN Organization
VideoLAN - makers of VLC Media Player, VLMC, and other video projects.
Network and Device Management Tools
Wireshark.org - network protocal analyzer.
Nmap - network scanner and exploration tool.
OpenNMS - monitoring and performance management for IT infrastructure.
OpenRemote - design and management tools for Internet of Things.
Zabbix - monitoring for infrastructure, services, and applications.
Productivity Software
Apache Open Office - office products like word processing, spreadsheets, and slides.
Rocket.Chat - team chat with a paid cloud hosting option.
IRC - very old, but very reliable team chat.
EspoCRM - web based CRM with a paid cloud hosting option.
OROCRM - another web based CMR option.
GIMP - well supported image manipulation program.
Scribus - desktop publishing software.
BRL CAD - solid modeling program.
LibreCAD - 2D CAD program.
Blender - 3D creation, effects, and non-linear video editing.
Inkscape - vector graphics program.
Open Project - web based project management tool with a paid cloud option.