This is a constantly evolving list of the current best post production software that is already freely available. Major emphasis is placed on copyleft and open source, but free proprietary alternatives have been listed when the pickings are especially slim. No skirting around any major flaws, if something isn't quite up to par to be taken seriously yet, I'm going to say it.

I hope to update this list and replace them as time goes on, since programs and possibilities are always evolving. If anyone has any video related suggestions that I missed, please let me know and I'll look into adding them to the list.

I'd like to keep it concise with the best contendors in each area and ignoring the stuff that doesn't have any aspirations beyond hobbyist. Userfriendly program lists have been shared to death already and I don't really care for software/tools that sacrifice power to make everything easy. That's what tutorials are for. Learn it, keep at it, and if you are serious, you can experience constant growth without being crippled by future limits in the name of simplicity.

Here it goes:

Animation

Blender - Blender really raises the bar in how open source creative software should be. It's a 3D modeler/animator that keeps pace extremely well with proprietary software that costs upward of thousands of dollars. The dev team is very active with a pretty regular release cycle, adding awesome features with every version. Also a large selection of user created extentions adds even more functionality/improves the workflow. It's going to take some time to learn, a lot of time to master, but in choosing this, the room for growth will be endless.

OpenToonz - Very recently Digital Video S.p.A. has released the source code to their Toonz animation suite under the BSD license. While not strongly copyleft, this release is big since this software has been used by major leaders in the animation such as Studio Ghibli. It is capable of doing both handrawn and cutout animation; the ui (xsheet instead of timeline) seems to favor the former, but the tweening capabilities are still present and the "plastic tool" allows you to deform your characters and rig them with bones with capabilities that comepletely trump the puppet tool in Adobe After Effects. Effect nodes and scripting capabilities really add to the power of what this software is capable of. The main site contains Mac & Windows installers & the source, but their is a hidden Ubuntu build maintained by Getdeb and a cross-distro appimage compiled/maintained by the devs of the next animation program on the list,**Thank you @AlchemyDoll for sharing this resource**

Synfig Studio - Originially a closed source in-house solution, 2D animator, Synfig Studio rose from the ashes of Voria Studios with a GPL license attached. While there are still some features to be desired (inverse kinematics, a true 3d workspace, and mesh deforming are what I'm hoping for), it has an impressive array of tools. For the past two years, they have experienced regular growth through crowdfunding and allowing donors to set the development priorities. This looks like it will continue in the future at a good pace and narrowing the open source/proprietary gap for animation. Their newer versions also integrate with the open source, mouth animating to audio tool Papagayo. The creators are simulaneously working on a creative commons series called the Morevna Project that allows them to showcase the features, while finding/eliminating any bugs.

Graphic Design

Darktable - The open source alternative to Adobe Lightroom. It allows you to quickly edit/maintain your raw photos and paste settings to multiple images at once. Their feature for removing photo noise is really solid too.

GIMP - I honestly can't say GIMP is that great right now, but they are working hard on a major port to GTK3 that once finished should allow them to bring their development at a faster pace where they can hopefully catch up better with the proprietary alternatives. It's a raster graphics editor and right now kind of feels like it is several years behind. When GIMP passes this hurtle, it could seriously give Photoshop a run for it's money.

Inkscape - Like GIMP, Inkscape is also going through massive internal optimizations that have throttled rolling out new features for years but are necessary for long term viability. The proprietary gap in terms of usability for professional work is currently even larger than GIMP (ie. they seriously need to fix their layer/object management), but as a vector graphics editor Inkscape is currently the only real shot at having an open source counterpart to Adobe Illustrator.

Krita - If you are creating raster art from scratch, there is no better option than Krita. Adjustment layers, groups, effects, and the ability to work with 32 bit images, Krita is an impressive package. One place it really shines, is it's integration with drawing tablets. Whereas GIMP's tablet support seems like a science experiment gone wrong, using Krita has been the smoothest/most customizable experience that I've ever experienced (even more so than Photoshop). Their new release also has solid functionaliy for hand drawn animations, for you animators who managed to maintain your analog muscles. **Thank you @yotra for posting about this**

Sound

Audacity - You might be surprised to know that there is much more to Audacity than meets the eye. Despite being so lightweight, it offers profiled noise reduction, support for VST plugins (see VST section), and a hidden spectrogram.

Ardour - Ardour is a bit heavier and greared for more complex multitrack situations. Both Audacity and Ardour shine in different areas, so in going the open source route, it's best to have both and choose depending on the situation.

Video editing

Unfortunately if you are looking for something professional, right now the open source options are pretty slim. Most seem to be stuck at iMovie-like quality, but there are good prospects for the future.

Kdenlive - If you need something open source to get going right now, this will be your best bet. It has a good array of features, supports the full ffmpeg gamut of formats, allows to edit 4k natively and with proxies, and contains all of your scopes. However keep in mind there is no xml/edl import/export so any project started here has to stay here for now and vise versa. While not available directly there are workarounds for a few major features that may be missed such as multicam and adjustment layers for color correction, so with patience you will see much more possibilites than meets the eye (especially when examining how their transitions/layer structure works). They have a monthly IRC meeting to discuss the direction that development takes. **Thank you @leoplaw for the suggestion**

Pitivi - As it stands right now, this software falls short, but they seem to have greater potential over other promising, solid foundation minded up and comers like Lumiera. Watch this one, play around with it, don't take it too seriously yet, but keep in mind updates are planned.

Da Vinci Resolve **CLOSED SOURCE** - Where other companies are imposing subscriptions and eliminating perpetual licenses, Blackmagic Design has done the opposite and released a solid/fully functional piece of software for free. This program started out as the industry standard for color correction but they now have a fully functional video editor that keeps getting better and better. The paid version costs $1000+ but that is geared towards larger scale productions. Unless you want to export out in 4k, have stereoscopic 3d, sync projects collaboratively over a network, the free version works perfectly for your indie needs. Be warned, to use this effectively you are going to need to have a pretty fast system, and a mindfullness of the formats you are putting into your timeline. It's also OFX compatible (see OpenFX below).

Visual Effects

Natron - Natron is ambitiously aiming to be a solid open source alternative to NUKE and growing steadily towards that goal. They currently are lacking in some important capabilities such as GPU rendering and a true 3D workspace. Still, it offers the power of a node-based workflow and support for OFX plugins (see OpenFX), and and has very active development.

Fusion **CLOSED SOURCE** - Another Indy freemium option offered by Blackmagic Design. It's a node based compositor, that is powerful and versatile enough to be used by the big studios in many blockbuster feature films. The restrictions in the free version seem a little bit heavier for Fusion than Da Vinci Resolve, but that's really not saying much because they are rare in both. If you do decide to go with Fusion, be sure to check out the hilariously titled "We Suck Less" forums as it is a gem in compiling a nice library of user created scripts/plugins.

More Tools

Avidemux - I wouldn't use this on it's own for any real project, but it does offer the ability to quickly and losslessly splice and join h264s without recompressing them which can come in handy in a pinch.

DisplayCal - This is a GPL solution for calibrating and profiling your monitor with a colormeeter. It's a known fact. The colors of what people see on their screens vary widely and yours probably don't look exactly how they should. If the colors of your screen are garbage, then your color correction will be garbage. The way this used to be done was through meticulous adjustments using color bars (which you might recognize from back in the day when a television station didn't have anything to air). Theoretically you could calibrate your computer monitor this way, but the process is a little complicated, imperfect, and you'll likely feel the creeping concerns that your efforts are arbitrary. Enter the colormeter. It's a nifty piece of hardware that will likely set you back a couple of hundred dollars, but will spare you a lot of potential stress down the road especially if you choose to freelance. Monitors both expensive and cheap will benefit from this, but don't expect it to make your monitor exceed it's hardware limitaitons. If you opt to use Resolve for your editing and color correction, I can't stress this enough, because the only other programs that can integrate your colormeter and Resolve seamlessly to calibrate a reference monitor will cost you around 1k. The initial set up may be a bit complicated, but it's well worth the initial effort and maintenance is easy. Their instructions are well documented and walk you through everything you need if you have the patience.

FFmpeg - A lot of tools mentioned utilize this command line video conversion software behind the scenes. It isn't very user friendly on own, but learning how to leverage it has merits.

Open Camera - Generally, it is ill advised to use your phone for shooting as there will be compromises in both the camera sensor and microphone which will produce sub-par results. However you can avoid the whole triple trainwreck of auto-[focus, exposure, whitebalance], by using this app which allows you to set it and lock it in. It is available in the F-droid app store. It even let's you shoot RAW photos if you switch to a different camera API. Through tests on my Fairphone 3, I was able to greatly exceed the maximum advertised video specs and shoot 100 FPS video at 1080p (VS 60 FPS at 720p).

OpenFX Plugins - Don't be mislead by the name. OFX plugins themselves aren't necessarily open source (it's fundamentally just a shared API), but that doesn't stop this from being something desperately needed. One, this cross program compatability gives a greater library of tools at your disposal, and two it helps make it easier to switch programs should the need arise. If your program supports OFX, you are likely to have access to some great (right now mostly paid) tools.

VST/AU plugins - If your editor supports these, you can reap the benefits of the vast amounts of independantly created audio processing plugins. Some well made freebies include plugins hosted at KXStudio, GSnap **CLOSED SOURCE** and BlueCat Audio **CLOSED SOURCE**.

youtube-dl - This is great if you need to rip video from the web. It goes beyond well beyond Youtube and can even support password protected content on some sites (if you have the login credentials. It's run via the command line, but there are various GUI's available for it. Just make sure to use this one ethically and know your fair use rights.

Best tools to make good videos as "open sourcely" as possible