Which project(s) made you go “I can't believe this is open-source”?😎

The Linux ecosystem as a whole

You have got to have one of the best names on this server (unless it is actually an error)
- No, it's my actual username

Definitely Blender. I'd consider myself a medium grade expert at using it for CAD, solid modelling, 3D printing, yet there are vast sections of it I have never touched, and appear to be so rich that you could build a career around them without overlapping with my skill set.

Blender used to be so difficult to use. It has come a long way and I genuinely like using now, not just forced to because of budget limits.
And like having full Python interface is insane for how powerful it can be even to begginers - but the crazy bastard made it easier with geometry nodes

-

Wait, osu! is open-source??
- -
- yup! I think the main dev makes so many changes that he's one of the top github users. No idea how to check that though I only heard it from a friend a while back haha
Kdenlive, just wow. I knew absolutely nothing about video editing, and it was so user-friendly, that it only took me a day to create something with it. Such great software.

Jellyfin, such a great little media server.

Yeah, the reddit community is great to... Need a way to bring them here. 😭
- @CCatMan @div, easy, show them tis analyse of Reddit, made with bLacklight. (the TowerData which appears is known to use even keylogger to profile the user).
  https://themarkup.org/blacklight

Firefox is the first to come to mind. Also all the KDE software (when run in KDE).

I wish Firefox used QT or there was a KDE browser that was better maintained
KDE's stuff is amazing.

Linux! The responsible for my knowledge in computing and a great deal of English..Linux is the power!

I switched to Linux Mint full-time a few months ago and it's blown me away with how good it is.
- After 13 years using Linux I still can't believe it's free!

VSCode. I know its owned by Microsoft but its such a good editor. Having a strong tool is so important since nobody wants to be concerned about the app, they just want to code and do their work!

Check out VSCodium. It's VSCode compiled without all the Microsoft bits.
- Love me some VSCodium. I honestly can't even tell a difference between the two.

Omnivore! It's just a "read it later" app, but so nice to use. I enjoy newsletters again, because they all go there instead of in my emails, and they all have a uniform look to them now. Sorting by labels and syncing highlights to my Obsidian inbox page are great features. And they said bulk editing is coming soon.

Also bitwarden, lichess, and qbitorrent.

For me it is KDE Plasma desktop. By far the most powerful, customizable, flexible and innovative of the computer desktops today. And despite all these features and power it is still one of the more lightweight ones.

Also there are other great KDE apps and GNU/Linux operating system in general. Just love how they respect my digital rights and freedoms and my privacy and I do not need to use proprietary alternatives which are just getting more bloated and include more and more spyware. Not to mention their constant dumbing down of the interface and closing it up.

As a creative: Blender. It was always a good program but thank god they finally started hiring people, that actually know how to design a usable UI. I remember the times when the devs refused to change the simple default selection to the worldwide standard: left mouse button.

Good lord I didn't know about the selection thing... I might be sick.
- Yeah and that's only the tip of the iceberg.
  
  Did you know that Blender use to unironically use Shift+Ctrl+Alt+C for a surprisingly common operation?
  
  I don't actually remember what for, 2.79 was years ago, but I think it placed the object origin at the center of the geometry

Honestly, Lively Wallpaper. You can set anything as your wallpaper and it'll work wonderfully: a video streaming directly from YouTube, a Unity game, a shader, a browser tab, a gif... You name it!

And the API supports sound input so anyone can make their sound visualizers now. I always wanted to do that as a kid after being an og WMP fanboy and finally got that knocked off my bucket list

This sounds cool but the amount of time that I actually see my desktop is probably less than 1% of the time I’m on my computer.

Yunohost
KDE Plasma
Kdenlive
Krita
Inkscape
Blender
OBS
Xonotic
Beyond All Reason
Manjaro (Despite the hate, no other distro has worked as well for me)
Firefly III
Grocy
Nextcloud
DisplayCal / Argyll CMS
Scribus
Natron
MuseScore
Jellyfin
Navidrome
QOwnNotes

...and so many more

OBS is the one that gets me. A lot of streamers I follow talk about how they use OBS because it's such a reliable standard and works the way they expect. Pretty cool that an open source app is the standard for something as mainstream as livestreaming.

I kinda have the opposite response. I've been a mostly open source guy for the last 20 years so when I see what kind of half baked proprietary tools people buy I'm always shocked how much money mediocre software costs.

Up until not too long ago, it seemed like if the leading proprietary tool was half baked, the open source tool was a quarter baked. Take office suites. OpenOffice was pretty consistently ten years behind MS Office. Or GIMP was constantly lagging behind Photoshop in usability, but now is a very good photo editor. The exception has always been development tools, where you get a nice confluence of motivation to volunteer and people knowing what they want.

Blender and KDE

Jellyfin
Blender
Darktable
Bitwarden / Vaultwarden

Darktable is awesome. People rave on about Lightroom like it's irreplaceable, but Darktable exists and is a legit alternative.
wtf BLENDER is open source???
- Yep, there are quite a few forks of it too, eg. one for artists with a friendlier UI, a CAD-focused one, a game engine one etc.
- the thing is, blender wasn't always open source. And they wouldn't have been this successful if they were still closed.

I'll reply in a kind of opposite to the subject. I can't believe there aren't any decent open source 3d CAD programs that are worth a damn.

What's wrong with FreeCAD? You obviously need to learn a new workflow with it, but that's true for all 3dCAD.
- I love FreeCAD and i use everytime I can. It has an incredible range of features and is (becoming) stable enough. But, sadly, the world of CAD is fu¢{|Ng proprietary, if you are not 100% compatible with the Autodesk stuff nobody will ever consider using it on a production environment (e.g. architecture or construction). And off course, Autodesk does it's best to keep file exchange uncomfortable

For some reason i thought Brave was closed source

OpenSSH!

Fedora OS. I mean, its a fully viable, up to date, no tracking operating system. After trying it im seriously thinking people buy windows only because they're used to it. Now it's my daily driver "even" for gaming (Praise our Lord Gaben and Proton).

As someone in IT I have mixed feeling about this. Linux machines make great servers, ok workstations, and God awful corporate endpoints. Say what you will about Microsoft and windows, when you need to manage policies impacting large number of endpoints, active directory (when configured correctly) is a beast of a solution.

Now if we are talking about someone at home browsing the web? Use whatever gui/os you like. I do agree, more people should try Linux just to be exposed to something different.

VLC and OBS

qbittorrent

Cura. I've been using it for over a decade, and it is still hands down the best 3D printing slicer. S3D (I think that was it's name) was on top for a while, but was ~$200 for features that really weren't worth the money.