If fugitive.vim is the Git, rhubarb.vim is the Hub. Here's the full list of features:

• Enables :Gbrowse from fugitive.vim to open GitHub URLs. (:Gbrowse currently has native support for this, but it is slated to be removed.)

• In commit messages, GitHub issues, issue URLs, and collaborators can be omni-completed (<C-X><C-O>, see :help compl-omni). This makes inserting those Closes #123 remarks slightly easier than copying and pasting from the browser.

If you don't have a preferred installation method, I recommend installing pathogen.vim, and then simply copy and paste:

cd ~/.vim/bundle
git clone https://github.com/tpope/vim-rhubarb.git
vim -u NONE -c "helptags vim-rhubarb/doc" -c q

In addition to fugitive.vim, Curl is required (included with macOS).

Provide your GitHub credentials by adding them to your netrc:

echo 'machine api.github.com login <user> password <password>' >> ~/.netrc

If you'd rather not store your password in plain text, you can generate a personal access token and use that instead:

echo 'machine api.github.com login <token> password x-oauth-basic' \
  >> ~/.netrc

If you are using GitHub Enterprise, repeat those steps for each domain (omit the api. portion). You'll also need to tell Rhubarb the root URLs:

let g:github_enterprise_urls = ['https://example.com']

How do I turn off that preview window that shows the issue body?

set completeopt-=preview

Like rhubarb.vim? Follow the repository on GitHub. And if you're feeling especially charitable, follow tpope on Twitter and GitHub.

Copyright (c) Tim Pope. Distributed under the same terms as Vim itself. See :help license.