Font awesome may the be king of easily embedded icons, but SVG Repo is a web developers dream for more diverse SVG vector icon sets.
SVG Repo offers you the ability to search, explore and edit the best-fitting free icons or vectors for your projects using a large library of vector icons. You can download SVG vector icons for commercial use for FREE. The sets are community driven, and as you would expect from an open-licensed project, you are encouraged to contribute too.
The only annoyance I see are small ads everywhere – but hey, everyone has to pay for hosting somehow.
USE:
For WordPress – Simply download the SVG support Plugin. You can use these as regular images in the media gallery.
< img src="/uploads/icon.svg" alt="triangle with all three sides equal" height="87" width="100" />
.svgclass {
background: url("/uploads/icon.png") no-repeat center;
background-image: url("/uploads/icon.svg");
background-size: contain;
}