This is another plugin that's inspired by text editors like WriteRoom, which aim to make writing as simple as possible.
You can use investigate to view the documentation for the current word in Vim in a few different places. Through your web browser, using Dash.app on OS X, or with an arbitrary shell command. View the Github repo for more information.
Keith suggests using the following remapping:
nnoremap K :call investigate#Investigate()<CR>. This allows you to invoke investigate.vim by pressing
K in Normal mode.