Aside from the obvious text editor (nvim-gtk) and terminal (tilix), Zim http://zim-wiki.org/ is probably my favourite -- it's a desktop wiki that I use for everything from note taking to planning and documentation.
Zim looks pretty cool. It reminds me of lightweight, HTML editors I used long ago. Also, makes me think one of them might be a nice substitute since they similarly have project's pages on the left. Categories and notes become folders/projects and individual pages. More powerful features maybe on content site. Maybe less on organization side since Zim is designed for that. I don't see much difference in usability if the editor was itself highly usable. Obviously, we aren't talking Dreamweaver or something. ;)
Are there specific features in this you think a HTML editor wouldn't have or would just be lots of trouble for?
Well, the HTML editing of Zim might be its weak point. The formatting is a bit finicky and if you change the styling too many times it sometimes gets in a situation where I cut-copy in a text editor and paste it back to restart with no styling.
Aside from that, it has lots of plugins and can easily be exported to a full website. In fact, Zim's website is made with Zim http://zim-wiki.org/.
Bu the killer feature is that it's a wiki: you can link pages together and easily re-organize them. It's fully searchable and you can embed rich content. Also, all the pages are stored as ReST documents (I would have preferred Markdown), which makes them editable with a text editor. Also, Zim can use Git or Hg for version control.
Zim strikes me as trying to get at some of the same features/conveniences of things like Notion (https://www.notion.so) or Slite (https://slite.com), though both of those focus heavily on the team-collab audience. Like, it’s an editor because, well, it has to be, like Evernote also has to be an editor, but the main point is the organization, hierarchies, access to nice simple default layouts you don’t have to code yourself, and nifty widgets/utils that know how to work with all the other parts. (Correct me if I’m way off base though, because I’ve totally not tried it yet.)
Zim actually seems like it might be exactly the sort of thing I’ve been looking for lately, though; have been trying out various things like the ones above (Notion, etc) and... not sure why, but apparently I don’t want to use anything that slick more than once.
Notion is actually really awesome, they got everything right, except the pricing (in my opinion). Zim is far from perfect, but its extensibility, plain-text storage format and most importantly, Wiki features make it quite useful.
I would love, however, to have Zim with a better editor, one that would use typed blocks like Notion.
Emacs with Evil mode -- I spent the last year learning vim and swore I'd never use another text editor. That's until I found EVIL mode in Emacs and have stuck with it since. My productivity has soared and still enjoy configuring the hell out of my setup.
Directory Opus. I'm not affiliated, but I'm such a fanboy, I just as well might be https://www.gpsoft.com.au/ My favorite piece of software hands down, it just keeps getting better, since the early 90s on the Amiga.
For photos I still use Bibble, which no longer exists (it's now Corel AfterShot Pro, no idea how good that is). But I love it, both on Windows and Linux. For example, you can set up hotkeys to run scripts on images, to I have one to output TIFF, resize, sharpen and save to .png with ImageMagick, then compress that to jpeg with guetzli. Perfect for me, I miss nothing.
UltraEdit https://www.ultraedit.com/ for coding because has so many options, and SublimeText for coding and note taking (I love that you can just close it with open, unsaved files, and get them back, apart from that it starts instantly)
Instead of the Windows start menu I use http://www.freelaunchbar.com/ for stuff I use often (unless it works on files, then it's a custom button in Directory Opus)
I don't use it often anymore, but this thing is hilarious to make, say, silly skits: http://www.livelooping.org/tools/software/ambiloop/ Set the length to 20 secs or something, start, say something silly, be quiet for 20 seconds, reply to what you just said, what 20 secs again, reply to the reply... the stupidity just writes itself! I bet it can also be used for good, but either way, I love this software, it sparks joy for me for sure.
DCSS is a game I am always interested in checking out again after a while, I love how they constantly change things in their quest to get rid of tedium an favor of interesting decisions: https://crawl.develz.org/
I'm sure there's many I forgot, I'll post an update when I have some more.
Haven't used it in ages, but it always was great for ripping audio CD's: http://exactaudiocopy.de/ Maybe there's something better by now, I honestly have no idea. For the sake of audio preservation, chime in if you know something more accurate, or that works better with modern hardware or what have you :)
Basic, text editors. They're fast, save things in efficient way, rarely crash, and have few security issues. I'm always firing one up by default until I get around to automating whatever I'm using it for or just a better app.
I've been long overdue to upgrade to something better. Plan to do that this year. Alternatively, might learn some formal methods with a trial project being a partly or wholly, verified, text editor. Maybe even one of the UNIX'y ones like vi or vim.