Free Software

Steam

Game and Software store. Easy to use and manage your library. Loads of community features.
Features:
Chat/Voice Chat
Easy Multiplayer
Mod Support
Huge Software Library
Often has deals
Free Games & Purchases

Windows, Linux, Mac

GOG

DRM free game store.
Features:
Self Install
Better Search
Better Interface
Search by deals option
Free games & Purchases

Windows, Linux, Mac

Ninite

This is a website that has a large list of software you can just click and download. It creates an installer and once you run it, it will automatically download and install everything without any other input. If you have a new computer or fresh Windows Install, this site should be your first visit.
Features:
A huge list of free software to install
No click install (Just run)
Can be used to update
Free for personal use

Windows Only

Duck Duck Go

Duck Duck Go is a search service that focuses on privacy.
Features:
Unfiltered Search
No blinders or search profile
No political filtering
Can search Dark web (if you’re into that)
Honest Raw Search
Free & Bing ads

All platforms

Brave

Browser that focuses on Speed, Privacy,and security.
Features:
Import data from other browsers
2-3x Faster than chrome
Built in ad-blocker(light, not all ads)
Low Profile, doesn’t eat system resources
Isn’t glorified Spyware like other browsers
Fingerprint Prevention
Free

Windows, Linux, Mac

Discord

The Best community chat system currently. Tailored for games, but any community could easily fit here.
Features:
Chat & Voice Chat
Good Image board
Streaming Live
Play & share videos
Free & Premium upgrades

Web based, Windows, Linux, Macs, Android

RocketChat

OpenSource Slack like chat system tailored for work communities. Designed to reduce the need for email.
Features:
Chat & Voice Chat
Video Conferencing
File Sharing
Options to self-host
Free & Open Source

Web Based, Windows, Linux, Macs, Android

Pidgin

A universal chat client. Huge support list with plugins.
Features chat support for:
Google Chat, Gadu-Gadu, IRC, Novell GroupWise, Lotus Sametime, Silc, SIMPLE, Zephyr, many old chat programs.
Plugins for- Battle.net, Campfire, Discord, Docker, F-List, Facebook, Gammu(SMS), Hangouts, Heros of Newerth, ICQ, Mumble, NateOn, NetNexus, OkCupid, Omegle, Twitter, QQ, RocketChat, Skype, Slack, Steam, TorChat, Tox, Trillian, Webchat, WhatsApp, Yahoo and more.
Free & Open Source

Windows, Linux

ThunderBird

Email client. Calendar, task management, Chat, RHS feed. Thunderbird is arguably the second email client in existence. Best in terms of easy to use. Loads of plugins modern plugins to get ahead.
Features:
POP3/IMAP/SMTP Client
Tabbed Mail
Email Search
Calendar
Chat
Free & Open Source

Windows, Linux, Mac

Zoom

A good way too setup meetings and interface over a computer and phone. Meets most people’s needs in the free tier. Easy to set up.
Features:
Video & Audio chat
Phone support
Schedule meetings easily
Host controls the call
Free tier

Runs on Windows, Linux, Macs, Android

Clipgrab

An easy way to download clips of YouTube and other streaming sites to your computer.
Features:
Download videos as MP4
Download Music as MP3
Loads of options and formats
Free

Windows, Linux

HandBreak

Video Transcoder. Take your DVD collection or other video formats and put it on your phone or any other device.
Features:
Preset devices
Command line for automation
DVD Transcoding
Free & Open Source

Windows, Linux, Mac

K-Light Codec Pack

Play virtually any video format.
Includes a lightweight classic Windows Media Player. Useful for old computers or if you want native support for any format.

Not a huge issue these days formats are almost standardized. Still if you find some unusual formats, this can usually open it up.
Free

Windows Only

Music Bee

A full feature music player and alblum organizer.
Features:
10-15 band Equalizer
Utilize high-end audio cards with WASAPI and ASIO support
Supports WinAmp Plugins
Volume Scaling to normalize volume streaming
Up mix to 5.1 surround or resample down to lower bit rates.
Syncs with a number of devices
Free

Windows Only

VLC Player

A media player with a huge list of support, video and music. Supports streaming and hosting video(files). I’ve heard you can broadcast VLC to a grid of devices to make a huge monitor.
Features:
Audio & Video Transcoder
Supports virtually any format
Lightweight
Free & Open Source

Windows, Linux, Mac, Android

LibreOffice

A free office suite with the same features as the Microsoft counterpart. However, there are very powerful features not offered by any other office software. Yea you can update the look, so it has a ribbon bar like MS Office has.
Features:
Doc Writer, Spreadsheets, Presentation, Drawing, Math, Database
PDF Creator
PDF Editor
Opens most document formats
Head programmers moved from Open Office  to Libre
Free & Open Source

Windows, Linux, Mac

Scribus

LibreOffice doesn’t cover everything, but if you want to make professional documents like in a magazine or product documentation, Scribus may be the way to go.
Free & Open Source

Windows, Linux, Mac

Etherpad

A unique document writer that allows many people to work on the same document at the same time. Unlike Google Docs which is cloud hosted, Ether pad sets up a local web-server. Once people connect to your local web server you can get as many people working on the document as you want at the same time.
Once the server is up just connect using your browser.
Free & Open Source

Windows, Linux, Mac (Server)
Web-based client.

Paint.NET

Have you ever wondered what a love child of Photoshop and MS Paint would look like? I haven’t, I don’t think anyone has. But Paint.NET is what it would look like. It’s a simple paint program with some advanced features in a superb interface. Most people can sit down and immediately use it.
Features:
Layers
Advanced selection options
Red Eye Removal
Supports many formats
Color balance/effects
Free & Open Source

Windows Only

GIMP

Graphic Image Manipulation Program. This image editor is a different animal than all others. It was created by programmers to do their images. It has some unique features that make it stand out from all others.
Features:
Customizable Interface
Photo enhancer tools
Color mixing and tuning
Unique hardware support
Free & Open Source

Windows, Linux, Mac

Krita

A painting program created by artists for artists. Krita focuses on concept art, texture and matte paint, illustrations and comics. I like how they put effort and care into the website and mascot.
Features:
Customizable Layout
Over 30 docks for additional functionality
Brushes and texture
Brush stabilizers
Vector tools & Text bubbles
Wrap-around mode
Free & Open Source

Window, Linux, Mac

OpenShot

Easy to use video editor that’s been around since 2008.
Features:
Unlimited tracks
Tile Editor
Easy Trim and slice tracks
Animation Key framing
Free & Open Source

Windows, Linux, Mac

Keden Live

Video editor that started out in 2003
Features:
Unlimited Tracks
Configurable Interface
Use any video/sound format
Audio and Video scopes
Many transition effects
Free & Open Source

Windows, Linux

Olive

A video editor that matches the feel of Adobe Premiere.
Features: Multi-Track Editor
Preview video
Key frame Animations
Chroma Key
Free & Open Source

Windows, Linux, Mac

Notepad++

Text editor, a good one too. The program installs a context menu to open any file in notepad++. If you have ever had a need to edit a config file, I recommend using this.
Features:
Color coding(helps with programming)
Powerful features like compare
Macros
Spellcheck
Free & Open Source

Windows, Linux

Process Hacker

Besides a confusing name, if you have ever opened up Task Manager and couldn’t do anything. I recommend this. This is a much more powerful version of task manager.  Showing network traffic, disk access. Kill process trees not just the programs and shows you background process. With a search feature and shortcut keys, this is a must-have.
Free & Open Source

Windows Only

WinDirStat

Ever need to find out what’s on your computer or what’s on it? This program is what I recommend. This creates a visual representation of every file on your computer in relation to how big it is on your computer. A visual map you can click on and explore. So you can see big programs, or programs that take up a lot of space with small files as it’s all color coded.
Free & Open Source

Windows only

Open Broadcaster

Need to record your desktop or stream to a website. Open Broadcaster can do that. What makes it nice is  how you can construct scenes. You can layer overlays, images and even video over gameplay or your desktop.