Here are some of the best. They are free open source programs and not trial versions. This list is by no means comprehensive but it does give you a place to start. If there are some you use and love, let me know so we can add them here.
Paint.net – http://www.getpaint.net/index.html
Image editing program with many of the features of expensive imaging software including layers, drawing tools, gradients and much more. It’s intuitive, easy to learn, has readily available tutorials and a forum where you can find answers to just about anything. Unfortunately, this program works on Windows only.
For all the Mac users out there, GIMP is still your best bet for free imaging software. It’s more sophisticated than Paint.net and works with Windows, too. Find it here: http://www.gimp.org/
Photopea is free online software that can handle PSD files, layers, clipping masks, and a lot more. You can simply go to https://www.photopea.com/ or add it from the Chrome Store.
If you’ve ever wished for a vector drawing program but just can’t afford Illustrator or CorelDraw, try Inkscape. Get it at: http://inkscape.org/ It isn’t quite as comprehensive as the commercial software but it is surprisingly close. For instance, it supports markers, clones, alpha blending and you can edit nodes, trace bitmaps and perform complex path operations. Create your own illustrated links. Yes, it’s as easy as right-clicking. Want to try your hand at mapmaking? Inkscape handles it and it works on Windows and Mac. Works in 2D only.
Open Clip Art Library at http://www.openclipart.org/ gives you free clip art in SVG or PNG formats without the risks of malware and other nasties so common on other sites. It is amazing! Graphics programs create what is called Scalable Vector Graphics or SVG files. Unless otherwise noted on individual files, it is all Public Domain even for commercial use. Use your free open source Inkscape and upload clipart for others to use. Giving back is always a good thing. It keeps the balance.
If you find yourself needing a 3D program, Blender may be your answer. Download it at: http://www.blender.org/ It works for all major operating systems and has an active community. If you are new to the world of 3D, there is Blender Quickstart and many tutorials including a huge collection specifically for beginners.Windows and Mac. Be sure and check out the official YouTube channel: http://www.youtube.com/user/BlenderFoundation
Video Editing can be done with simple software that is part of Windows and Mac but when you want to step it up beyond that, there are some alternatives.
Avidemux gets high ratings for ease of use, great tutorials, and it even has support for MKV. Get it here: http://fixounet.free.fr/avidemux
AVS Video Editor gets good marks from users but is available only for Windows. It’s part of a whole suite of products that includes an audio editor, video and audio converter, image converter, as well as DVD authoring and copying. CNET gives it a 5 star rating. Have a look: http://www.avsmedia.com/
For Linux/Mac there is the award winning Cinelerra. We are talking true broadcast quality. The interface is similar to Adobe Premiere Pro but it also has some of the attributes of Adobe After Effects and Shake. This software is not recommended for the newbie or those who are faint of heart but it does pack a professional punch. If you are on a Windows platform, you can try it out before making any major changes to your computer. Get it here: http://cinelerra.org/
Another option is the cross-platform OpenShot 1.3.0 with loads of transitions and effects including 3D animated title sequences. See it and download here: http://www.openshot.org/
Music Recording & Editing
Audacity is a free cross-platform sound editor for both recording and editing. It’s simple to use and fast. You can also convert all your old tapes and records with it. Supports VST Plugins but is separate because of licensing (not all are free). I’ve cleaned up many a track with this software: http://audacity.sourceforge.net/
For Windows users, there’s Kristal Audio Engine but be warned. It requires a minimum of 1 Ghz so if you don’t have at least that, don’t even think of installing it. If you are exploring recording, mixing and mastering digital audio, then you just might love it. Handles only 16 tracks at the moment but may expand soon. If you are a complete newbie, this will be more than you can handle anyway so you’ll need some tutorials. They are readily available online by searching Google. Note that some plugins are not free. Get the software here: http://www.kreatives.org/kristal/
Public Domain Music
If you are not musically inclined but want some instrumentals for the fantastic videos you have created, find some here: http://www.opensourcemusic.com/
Or go for the motherlode of free music at: http://www.archive.org/details/opensource_audio
Credit where credit is due
All the photos in this article are from another fabulous resource: morgueFile
It’s a public image archive free to search and free to use. Some photographers like to know where their work is being used while others do not. Comments are always welcome.
A final thought
Remember to check the Public Domain and Creative Commons licensing associated with all photography, clipart, music, or anything else someone has created for you to use online. Some are personal use only or require attribution. Others require no attribution and are free for all uses including commercial. It’s there for free and the best way to say thank you is by following the terms.
Remember, if you like what you are using and the developer accepts donations, be sure to send something! It doesn’t have to be a lot but it is a great way to say thank you and keep free software available.