Bootstrap Icons by Mark Otto
One of the most popular front-end frameworks, Bootstrap has now released its custom designed icon library designed to work with its components but also in every other project. Although it's an alpha release, which means that things are going to change rapidly, it has more than 1000 well-crafted icons ready to be used.
The release comes with its own standalone dedicated website and documentation and a few different ways to use them from your designs, to your code directly.
About the creator(s)
Main author is Mark Otto, who along with J. Thornton released the framework initially while working on Twitter. Otto is now a Principal Design & Brand Architect at Github and you can learn more about him at his personal website.
Of course, there were numerous contributors from the team that maintains the framework but a key contributor worth mentioning is @XhmikosR.