Daniel Steven Smith is a programmer and science fiction hobbyist who maintains a "Fantasy Fonts for Windows" website.
In 1997 he created Tengwar fonts, the first being titled "Tengwar Quenya" and "Tengwar Sindarin" (the fonts have the same keymapping, the names have nothing to do with the languages themselves). Since then he created other variants (ornamental/capital tengwar shapes etc) and Cirth fonts.
Dan Smith had to devise a keysetting to fit the tengwar into the keyboard. He decided to divide it into rows and series like the tengwar table. That way for example, the first 4 Tengwar are assigned to the leftmost row of the keyboard: 1, q, a and z correspond to the Row I (Tinco, Parma, Calma, Quessë), the next 4 keys correspond to the Row II etc.
This system has been followed by other font makers for their tengwar fonts (for example Parmaite, Elfica and Annatar), therefore maintaining compatibility to Smith's unofficial "standard".