Writing software code can be a painstaking and stressful process—and downright boring when the job is repetitive and you're doing it remotely, alone in front of your screen.

To liven things up, many developers and testers use humor to relieve the monotony and connect with their virtual colleagues by sharing a joke. Over time, it creates a bond with fellow developers, though the humor and creativity slipped in between the lines of code are invisible to the rest of us.

"Humor creates relationships between people who are physically distant and is a good way to stave off boredom," said Benoit Baudry, a professor in the Department of Computer Science and Operations Research at Université de Montréal. "It's a way to build engagement." Until recently, Baudry was at the Royal Institute of Technology in Stockholm, where he and his colleagues studied the special humor of developers.

"Developers are people who love software," said Baudry. "So they try to create emotional bonds using the digital technology that is their work tool."

But they have to exercise some caution about when and where they insert jokes and comments. They don't want any of their jests to end up on Instagram.

To find out more about how they do it, Baudry and his fellow researchers circulated an online questionnaire that was posted on developer sites. More than 125 developers from around the world responded. They reported using humor most frequently in test inputs and "commits," or changes to the code. A sly dialogue unfolds between the test lines.

The research was published in the Proceedings of the 46th International Conference on Software Engineering: Software Engineering in Society on June 6 and is also available on the arXiv preprint server.

Darth Vader, Luke et al

Baudry and his co-authors looked at Faker, a library that generates random data for use in testing code. Instead of lorem ipsum—a sequence of meaningless words commonly used as a placeholder for text on a page until it can be replaced by the real thing—developers will sprinkle their lines with cultural references such as allusions to Seinfeld or quotes from poets.

"Some references are fairly specific, others are universal: who doesn't know the characters from Star Wars or The Matrix?" said Baudry. Characters from cult films are frequently used in titles, as are quotations. An example from Faker: "The wise animal blends into its surroundings" (a quote from the movies Dune). Nothing edgy or inappropriate, just light-hearted asides through which developers signal their interests and elicit a smile from their colleagues.

"Personally, I like to use characters from the 1998 film The Big Lebowski in error messages," said Baudry. He is also enthusiastic about lolcommits, a utility that lets developers send a selfie when they make changes to code. "These pics foster bonds with colleagues and are a way to celebrate when the job is done," he said.

The pioneer who paved the way

The trailblazer for quips in code was the brilliant NASA engineer and computer scientist Margaret Hamilton, who led the team that designed the system for the Apollo 11 lunar landing program in 1969. When the code was made public, people could see that it was peppered with jokes, Shakespeare quotes and references to The Wizard of Oz.