Icon fonts are a great way to add icons in your project without using images (using only pictograms). The main advantages are smaller file sizes (compared to images) or less requests. Fontomas is a web-based project that is open source and allows you to combine items (icons) from multiple iconic fonts and create a custom and lighter font.
Fontomas provides 3 built-in fonts (Iconic, Web Symbols and Entypo) and using just a few clicks you can select any letters from the icons, re-arrange them and export your new font. The exported font is in SVG and to make online fonts you can use generators like FontSquirrel.