1TinyLink - One Tiny Link allows you to reduce long links from websites such as Facebook, Twitter, YouTube, Linkedin as well as other sites on the internet for free.
Lstu - A nice and open source url shortener. You can use it as service or install it on your own server.
Polr - An open source URL shortener. A great non-profit and free alternative to bit.ly, TinyURL, or goo.gl.
Akari Link Shortener - Anime-themed URL shortener.
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.
T2M - T2M URL Shortener is an all-in-one link management platform which focuses on quality of service with easy-to-use interface at affordable price, backed by exceptional customer support.