NEW on the list. 

Free online classes and nanodegrees for the digital economy.

Website: udacity.com
Cost: Free and premium versions
Availability: Online

Top 100 Tools for Personal & Professional Learning 2018: 80
Top 100 Tools for Workplace Learning 2018: –
Top 100 Tools for Education 2018: –

Past Overall Rankings
2017: –    2016: –    2015: –    2014: –    2013: –    2012: –    2011: –    2010: –    2009: –    2008: –    2007: –