vimpc is a curses-based client for the Music Player Daemon (mpd) that draws inspiraton from vi/vim. It supports a vim-like rc file, mappable key bindings, normal/ex modes, counts, searching, a music library, directory navigation, playlist editing, and comprehensive help, is highly configurable and customizable, and more. It is written with the intent to make vi users feel at home when using mpd, but is also intuitive and very usable by non-vi users.
vxref provides integration of the xref tool into vim. The xref tool is a cross referencing and refactoring tool with a free version available that parses C and Java code, and a paid version that parses C++. vxref brings solid auto-completion (as opposed to all sorts of flakey varieties such as omni-complete) and accurate code browsing with scope information to vim.