Transparent and open finances.
DadsWorksheets.com has been a source of online teaching materials for primary grade mathematics for over 10 years. The site currently has over 8,000 printable PDF worksheets that are used by thousands of parents and educators daily.
As the web has evolved from delivering static content, the site has evolved to provide more interactive content including classroom tools, math games, teaching calculators and more.
None of this enhanced content would be possible without the many open source projects that make modern web development possible. A hearty thank you to all of the open source developers out there who are working to make web development better for everyone!