Zeal

Do you miss the days of Visual C++ 6 when you had the entire MSDN documentation offline for access? Dash is a Mac app that does that for a whole bunch of languages and libraries. And if you are on Linux or Windows, Zeal is a clone of Dash that does the same.

Install

To install Zeal on Ubuntu:

$ sudo add-apt-repository ppa:zeal-developers/ppa
$ sudo apt-get update
$ sudo apt install zeal

To install on Windows, just use the installer download.

Docsets

At installation, Zeal has no documentation, called docsets, for any language or library. Go to Options and download the docsets for whatever you use regularly.

Once the docsets are installed you can query any word by typing it in the top-left box directly. If you want to query in a specific docset, C++ for example, use the prefix c++:

Options

Zeal puts a system tray icon by default. But, it appears in the top-left corner of my display instead. This overlaps with the close button of windows, which is irritating. So, I disable the system tray icon by going to File -> Options and disabling Show system tray icon.

Invoke Zeal from Vim

The icing on the cake is that you can now query any word in Vim and view its documentation directly in Zeal. I do this by adding this line to my vimrc:

nnoremap <Leader>z :!zeal --query "<cword>"&<CR><CR>

Just press \z on any word in Vim and bingo, I have the documentation for it in Zeal!

Tried with: Zeal 0.1.1 and Ubuntu 14.04