- Automatic compilation and error mapping into the codebase (supports make and parses gcc output by default).
- Function definition traversal with tags.
- File traversal over #include statements
- Syntax highlighting.
- Word completion with both on-page and tags file support.
It's sometimes easy to forget, but vanilla vim is a fully featured IDE for C. All this is really doing is extending that IDE functionality to support other languages, and adding innovations which have been made in other editors.