I do most of the stuff on Thinkpad T-Series laptops. As for the operating systems, I use Linux (Kali, Debian, Arch), openBSD, as well as my own build of LineageOS, Emacs (??)...

I am typing on a personalized version of programmer dvorak keyboard layout. The reason for that is to avoid developing RSI in future, which happens often for long time emacs users. As a side effect, this works like a security feature, so that no one except me can type on my keyboard.

I live inside Org-mode in Emacs which is incredibly powerful and extensible. I still have a terminal open all the time (Termite) which has tmux/Tmuxinator with my current sessions opened. On Android, I started recently running my own Python scripts (my preferred language of choice) inside Termux.  Org-mode files are synchronized on Android also with Syncthing, and I use Orgzly to work with them.

I don't like reading/writing office document formats, so I tend to avoid those whenever possible. I generate my PDFs with LaTeX (inside Emacs of course), and read them in Emacs as well using PDF-tools, or sometimes alternating with zathura. Emacs can show images too, but when I'm in the terminal I tend to use sxiv instead.

I store my secrets locally with Password-Store and synchronize them between devices the same way I synchronize my Org-mode, dotfiles (plus stow), git repos, etc... using Syncthing. I use Rofi extensively, plus Rofi-pass to type the passwords from the Password-store, and a custom Bash script that will perform web searches on the search engine I selected inside Rofi. This makes it so much faster to look up something on Wikipedia or YouTube, or some exotic search engines like Shodan, BinaryEdge, SecurityTrails, etc...

I browse mostly from EWW (Emacs) and qutebrowser when text is not enough. I do most of my reading in Elfeed (Emacs) with Elfeed-protocols to connect to my own TT-RSS server that follows ~300 RSS feeds, and has a big set of filter rules to mark most of the articles as read (I still see lots of trash, so I'm constantly improving those rules, but I hope to filter out the garbage much better in the future).

I debug stuff with radare2 and GBD(+PEDA <3). I'm writing exploits in Python, using pwntools (yes, in Emacs).

I use mitmproxy as a web proxy to test web applications. I have previously used ZAProxy but have switched to mitmproxy because I can easily extend it with python, and write my own addons.

I also track finances using ledger-cli (with Emacs)...

I use awesomewm as a window manager (not Emacs... yet... I know exwm, but I'm not ready for that just as yet)...

My setup is pretty much constantly evolving, and I have a huge list of things I want to improve still, so I will try to keep this page updated once I change something.