LaTeX is ASCII, so no need to enter unusual characters. But LaTeX notation seems like a convenient way to enter mathematical characters even when not creating a LaTeX document. There are LaTeX input methods for Mac OS X, Emacs, and X Windows here:

https://github.com/clarkgrubb/latex-input

vim has good support through digraphs, :digraphs will list them, and then to enter, either C-K <char1> <char2>, or <char1> <BS> <char2>

for example ö is C-K o : or o <BS> :

see http://vimdoc.sourceforge.net/htmldoc/digraph.html for more details

Despite knowing vim digraphs I personally use XCompose for that these days. It's easier to configure and I can use the same shortcut for every program, wich makes memorizing vim digraphs useless.

I'd mostly agree, but vim's digraphs are kind of essential when using gvim, since GTK+ seems to have an inexplicable vendetta against custom .XCompose files.

I don't know what to say. I am using gvim and my .XCompose settings seem to be fine. And I don't remember me having any troubles with that so I would have to fix something ever…

As it turns out, you're completely right. Oops.

In case anyone else happens to have the same issue, I solved it by sticking

  export GTK_IM_MODULE=xim

in /etc/environment .

Thanks, I can't believe I've been using Vim without knowing about this. The mappings for greek letters are particularly easy to remember.

Slightly less relevant, but if you use Mac OS X, this type of support is also available generally. For instance, Option+E then E results in é.

But isn't that extremely limited? Does Mac OS X have keyboard shortcuts for entering greek letters or the infinity symbol.

It's absolutely very limited. It has a shortcut for ∞ (Option+5), but "Greek letters" is too large of a set for the space provided.

But being able to do that let me do data entry on documents written in Swedish (which has the additional characters of é, å, ä, ö, and à) after about 10 seconds of ramping up figuring out where the desired keys were.

I'm sure there's a summary somewhere on the interwebz.