BUILDING SINCE 2005 · NOT REVIEWED BY MICHAEL
Michael
Hartl
“You might know me as the founder of Tau Day and author of The Tau Manifesto , as the creator of the Ruby on Rails Tutorial , or as cofounder and principal author at Learn Enough”in their words · michaelhartl.com
7
products
2005
building since
Career
Every main product, who ran it, and when it changed hands.
Softcover2014 →
NOW
Tau Day2010 →
NOW
Learn Enough2015 – 2022
sold
→ an undisclosed buyer
Ruby on Rails Tutorial2009 – 2022
sold
→ an undisclosed buyer
Insoshi2008 – 2009
✕
Quark Sports2005
✕
Side projects1
RailsSpace
20052007200920112013201520172019202120232025
Michael runs ita new owner runs itsold, with the stated priceshut downside project
The journey
Rails Tutorial (2009), Tau Day (2010); sold Learn Enough (2022)
Latest
Jun 2025Tau Day: Tau featured in Apple's iOS, Google's official calculator and the Python programming language; Tau Day featured in Science News and The Wall Street Journal
by Aug 2022Sold Ruby on Rails Tutorial to an undisclosed buyer
by Aug 2022Sold Learn Enough to an undisclosed buyer
Aug 2022Ruby on Rails Tutorial: Produced seven editions of the Ruby on Rails Tutorial
Jan 2016On Software Engineering Daily, Learning Rails with Michael Hartl
How sure are we?
8 verified by someone other than Michael42 stated by Michael in public0 outdated, older than our limits
Read on 11 Oct 2026 · more data coming