vim-tag-comment (GitHub: mvolkmann/vim-tag-comment, License: MIT) is another small but useful plugin by Mark Volkmann. This one adds/removes XML comments, but instead of adding a comment to each line it'll use one multi-line comment instead.
It's not quite as simple as wrapping a visual selection in the comment syntax, however. It'll try to wrap a given element, so if you've got nested elements they'll be included in the comment. The commands for this are
It comes with some built-in mappings:
I've noticed people like shortcuts for commenting code. I prefer to just delete code myself, but it depends on how you work.