Software
I use Manjaro Linux with the tiling window manager i3. 1
For taking notes, I use org-mode in Spacemacs. It is simple, has Vim keybindings, and can render inline LaTeX fine. I also use Spacemacs to write LaTeX documents.
I write lots of code in Vim, helped by YouCompleteMe installed with vim-plug. Here is my .vimrc.
For more complex projects, the open source version of Visual Studio Code is fine, especially for remote development over SSH. 2 Of course, all of the above support Vim keybindings.
For web browsing, I use Firefox with the extensions: vimium, OneTab, Tree Style Tab, Enhancer for Youtube and uBlock Origin.
Hardware
I have a 2019 Asus Zenbook 13. It’s very portable, Linux worked out of the box, and the battery lasts for ~8h of work. The keyboard is awful, though.
When working from my desk, I use a wireless Microsoft Ergonomic Sculpt keyboard3, and an external vertical monitor. This setup is great for reading papers.