This is a list of all the open source software I have come across and use frequently to semi frequently. There will be some overlap with stuff everyone has already posted.

Photography and Image manipulation

• Darktable → RAW photo processing
• GIMP→ Photoshop alternative
• Krita → Digital painting (have only used it a bit, but I hear it’s good)
• Inkscape → Vector Graphics
• Automatic1111 → Diffusion model AI toolkit (mostly Stable Diffusion but also has extensions for other diffusion based models like OpenAI’s Shap-E)

3D modeling and Printing

• Blender → 3D Modeling, sculpting, 2D animation, compositing all rolled together (simply one of the best examples of FOSS)
• Meshroom → Photogrammetry
• PrusaSlicer → 3D printing slicer based on Slic3r

Video editing and Processing

• Kdenlive → Genuinely good video editor
• FFMPEG → Command line media toolkit (very complex but also works on android through Termux)
• Instant NeRF → Neural Radiance Fields, think photoscan to a 3D representation (not meant to make 3D meshes unfortunately)

Misc

• Calibre → E-book management
• Serge → Self hosted Local LLM’s made a bit easier to deal with
• Firefox → Web browser

FOSS I’m excited for

• DragGAN → Manipulate images by intuitively dragging, more on this here and here (official code being released this month but there are already projects based on the paper with working examples)
• CoDi → “Composable Diffusion” Any2Any conversion Txt2Vid, Vid2Audio, Audio+Txt2Img, whatever
• Neuralangelo → Promises to be NeRF’s for 3D models (don’t know if it will be FOSS but I’m hopeful)

My last experience with Win10 vs now:

(FOSS in bold)

• Edge -> LibreWolf, Brave
• Windows Mail & Calendar -> Thunderbird, Tutanota
• Windows Explorer -> Thunar, PCManFM
• Todoist/iCal -> fruux + Thunderbird
• NCH VideoPad -> Kdenlive
• iTunes, Spotify -> CDs, Audacious, DeaDBeeF, Bandcamp
• VLC -> mpv, Parole
• OneNote -> Obsidian Joplin + Backblaze B2
• Firefox Lockwise -> Bitwarden
• WPS Office -> LibreOffice, ONLYOFFICE
• VSCode -> Micro
• Visual Studio -> Micro + GCC + Glade
• Finale -> MuseScore
• NT -> Linux (obviously)
• Windows 10 -> Debian, Arch Linux

And now, the online services:

• Ecosia -> LibreX
• YouTube -> CloudTube
• Twitter -> Mastodon
• Reddit -> Libreddit, Lemmy
• Dropbox, Google Drive -> MEGA, Filen, USB sticks
• Blogger -> Neocities, Flounder (gemini protocol)

Sorry for the long post. Here are some potatoes:

CMUS as a music player. Clean interface, lightning fast and plays anything. I use it daily.

I’ve personally been using AlternativeTo for many years to find alternative software, especially when I first began using Linux.

I think most of them I’d be using on windows as well. Like blender, gimp, krita, librewolf, libreoffice, thunderbird, virtualbox, etc… etc… etc… Although it was 15 years ago I had switched to mostly open source applications in the years prior to eventually switching to linux entirely.

I recommend https://alternativeto.net/ since you just type in the software name and it will show alternatives rated by popularity. You can filter by many things including “open source”.

Been using Gimp for over a decade over Paint/Photoshop.

Kdenlive is pretty nice.

Calibre is very powerful for book management, you should stick with it.

Not a replacement per se, but I am just amazed by how much better some common FOSS apps feel in Linux compared to Windows. Apps like VLC, Calibre, FreeCAD, Libreoffice, hell even Firefox are so much smoother in a UNIX system, almost like THIS is their real home!

• Inkscape as well for all of the Adobe stuff
• Pandoc and Pympress for all my presentations
• Claws Email
• Khard + Khal + todoman + vdirsyncer for the rest of the PIM stuff
• Zathura is my PDF reader
• Syncthing replaced GDrive more or less
• qutebrowser

I switched to Linux in 2006.

Calibre is excellent for ebook management. If you are just using it to sync with your ereader you might be able to do without. I have a Kobo and use Calibre but will likely stop doing that because there are now tools that are a lot lighter to convert epub to kepub and add covers, etc.

I keep a list of software I like to use, I need to update it.

What distro did you choose?

Whenever I use Windows I can’t get over how utterly terrible the basic file explorer is. I swear that it was better back in the XP days. On linux I use Dolphin and have found it to be excellent. Tabs, Split screens, everything is so usable.

I’ve used Thunderbird since it was released almost 20 years ago. It has some annoying bugs around setting up accounts (get your password right or it clears the whole form), but you do it once and it works wonderfully.

LibreOffice (and not OpenOffice) is a must.

I have tried really hard to make the switch to GIMP, but Photoshop is too engraved within me.

I will probably keep using Photopea instead.

Calibre is great for book management. I use Thunderbird for my email/calendar since I’m on Linux and have never even though of changing. Works like a charm and it does everything I need it to.

Other software I use and recommend are:

• Web browser: Firefox
• Image and drawing: GIMP and Inkscapr
• Plain text editing and programming: Neovim
• PDF reader: Okular
• Media player: VLC
• Terminal: Alacritty (main terminal) and Yakuake (to have a terminal that I can easily access and then hide)

I love Notepad++. I use notepad apps way more than I should, but I really prefer the lightweight, no formatting text editing experience. It’s lightweight and can be installed as a portable version and supports all kinds of languages and plugins.

Edit: I suppose this isn’t in the spirit of the question though since Notepad++ is not for Linux. Still it’s an alternative to a Windows program that’s FOSS. (2/3 on topic)

Notepad->kate