Open source
Fontello
Web tool to build your own icon font from SVG files
Icon LibrariesBuild your own icon fontInactive
12 tools like Bootstrap Icons, chosen by what they do. About Bootstrap Icons

Web tool to build your own icon font from SVG files

Large consistent icon sets in SVG and PNG formats
Icon sets in several styles, with free and Pro packs

Icon and stock photo library made by independent creators

Open source UI icon pack with 480 icons for common actions
Simple open source icons drawn on a 24x24 grid
Open source neutral icon set for designers and developers