This plugin overwrites CTRL-f, CTRL-b, CTRL-d, CTRL-u, zt, zz, and zb with code that scrolls the lines fluidly to help the user know how far they are scrolling in the file. Plus it's good looking.
This is a Pathogen compatible plugin. It requires no configuration, though it can be tuned.
This plugin was forked from terryma/vim-smooth-scroll which does not support zt, zz, or zb.