Grab some text and "send" it to a GNU Screen / tmux session.

VIM ---(text)---> screen / tmux

Presumably, your screen contains something interesting like, say, a Clojure REPL. But if it can receive typed text, it can receive it from vim-slime.

The reason you're doing this? Because you want the benefits of a REPL and the benefits of using Vim (familiar environment, syntax highlighting, persistence ...).

Read the blog post.

I recommend installing pathogen.vim, and then simply copy and paste:

cd ~/.vim/bundle
git clone git://github.com/jpalardy/vim-slime.git

If you like it the hard way, copy plugin/slime.vim from this repo into ~/.vim/plugin.

By default, GNU Screen is assumed, you don't have to do anything. If you want to be explicit, you can add this line to your .vimrc:

let g:slime_target = "screen"

When you invoke vim-slime for the first time (see below), you will be prompted for more configuration.

screen session name

This is what you put in the -S flag, or one of the line of "screen -ls".

screen window name

This is the window number or name, zero-based.

Tmux is not the default, to use it you will have to add this line to your .vimrc:

let g:slime_target = "tmux"

When you invoke vim-slime for the first time (see below), you will be prompted for more configuration.

tmux socket name

This is what you put in the -L flag, it will be "default" if you didn't put anything.

tmux target pane

":" means current window, current pane (a reasonable default)
":i" means the ith window, current pane
":i.j" means the ith window, jth pane

{Visual}<leader>s to send visually selected text.
<leader>s{motion} to send motion text.
<leader>ss to send the current line.