I still haven't seen anyone using a spellchecker in code outside of IntelliJ
Eclipse has had an integrated spell-checker, which I believe is on by default for most file types, for like approximately forever. Now maybe everybody turns it off, but I gotta imagine there are some people who like it and keep it on.
I recently found https://github.com/tekumara/typos-lsp that uses https://github.com/crate-ci/typos Plenty of GH stars so likely a solid user base. Works great in NeoVim with the built-in apellchecker.
Codespell works very well, in my experience. I run it from the command line and in CI.
Emacs has the ability to do spellcheck inline, both as a run through the buffer (old-school style) and as an as-you-type live feature. That said, I do most of my coding in JetBrains IDEs these days.
For Vim/Neovim users, there is one built in that is pretty good, and once you've added frequent custom words to the dictionary it is great. You can turn it on with `:set spell` or off with `:set nospell`. Add custom words by pressing `zg` on the target word:
I have this in my vimrc file so it's on by default for certain file types:
" Turn on spellcheck for certain filetypes and word completion.
" words can be added to the dict by pressing 'zg' with cursor on word.
autocmd Filetype markdown setlocal spell
autocmd Filetype gitcommit setlocal spell
set complete+=kspell
" Don't highlight in red an underscore (_) in markdown
" https://vi.stackexchange.com/q/18471/17441
autocmd Filetype markdown syn match markdownIgnore "\v\w_\w"
> custom additions
You can also add it directly when using it. Move the cursor to the word and (I forget the command...) can add it as a rare word, good word or bad word.