Bitly - Get the most out of your social and online marketing efforts. Own, understand and activate your best audience through the power of the link with Bitly Enterprise.
Polr - An open source URL shortener. A great non-profit and free alternative to bit.ly, TinyURL, or goo.gl.
Rebrandly - Rebrandly is the easiest way to create, share and manage branded links.
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.
adf.ly - Earn money for each visitor to your shortened links with adf.ly!
Kutt.it - Kutt.it is a free and open source URL shortener with custom domains and stats.