This font is a slightly modified version of the excellent iA Writer Quattro S font. For more information about iA Writer Quattro, please see the announcement post.
Despite its excellence, iA Writer Quattro S does have a key flaw: the different weights of the fonts are not tagged appropriately, leading software such as fontconfig to load the wrong weight. I decided to fix this.
In accordance with the OFL license, I have renamed the font to Tabula Quattro. Please examine the copyright statements and license files for more information.