The plugins can be found from http://www.vim.org/scripts
1. Tagbar
It displays tags of the current file in the sidebar. You don't need to create a
tag file by using ctags. These tags include macros, namespaces, classes, and
function signatures, etc.
Personally speaking, It does better than taglist.
2. CCTree
It is used to display the calling tree of C code. It needs cscope file
3. clewn
This plugin helps you interact with GDB. Once you have to debug your program,
it is very helpful. You can see the source code in your vim buffer, send
command to GDB and see the result from another vim buffer too.
4. clang_complete
It helps to complete C/C++/Objective-C code in your development. Besides that,
it also displays warnings and errors regarding your code.
5. refactor
It provides some basic functionalities to do refactoring for C/C++.
6. stlrefvim
View STL reference within VIM.
7. CRefVim
View C reference within VIM.