Kutt.it - Kutt.it is a free and open source URL shortener with custom domains and stats.
PixelMe - URL shortener for savvy marketers
YOURLS - YOURLS is a website that contains all the tools you need to create and launch your very own URL shortener. URL shorteners like bitly or TinyURL are fine for public use, but they offer limited options in terms of URL customization.
Short.io - Short.io makes short links (vanity urls) on your own domain. Free signup, analytics and API. Chrome, slack, zapier and segment integrations.
Polr - An open source URL shortener. A great non-profit and free alternative to bit.ly, TinyURL, or goo.gl.
chl.li URL shortener - A simple, modern, free and privacy-friendly URL shortener.