Testing Text Tags (repeat ten times) Marcus Fehn on Mar 17, 2012 One of our test environments. This one’s to ensure the tagging engine works as expected (it does). Marcus Fehn Hot-tempered co-founder and interface designer. Back in 2002, Marcus wanted to write a novel but struggled to find a suitable tool. He came up with a design of his own, which, over time, turned into today’s Ulysses.