The ongoing feud between Wordpress and WP Engine is threatening open-source principles and good name

A hot potato: David Heinemeier Hansson was recognized as "Hacker of the Year" for developing the open-source web framework Ruby on Rails in 2004. The Danish software engineer has joined the clash between Automattic and WP Engine over the future of WordPress, stating that both companies are wrong.

WordPress creator Matt Mullenweg is trying to force WP Engine to surrender part of its revenue to his company, Automattic, and the feud's repercussions are rippling throughout the open-source community. Mullenweg has demanded a royalty fee of eight percent of WP Engine's monthly revenue for continued access to Automattic's WordPress servers and resources.

However, Ruby on Rails creator David Hansson says Automattic is entirely out of line. In a recent opinion piece on his blog, Hansson noted that the for-profit company is violating the foundational ideas of open-source development. He believes Mullenweg's actions do not honor the principles set by the GNU General Public License (GPL). Automattic's "nuclear" war against WP Engine threatens the entire open-source movement, and the potential damages could go far beyond the WordPress incident.

Hansson's popular open-source Ruby on Rails web tech is a prime example of how the GPL is supposed to work. Companies and individuals have used the framework to create ventures worth hundreds of billions of dollars. Some have given back by supporting the Rails Foundation or contributing to the code's improvement, while others have not.

The point is that Hansson has never demanded anybody pay a dime to use his creation. Once a developer starts charging for his product, the code is no longer open-source--it's proprietary, which falls under completely different licensing rules.

Under the GPL, open software is free to use without warranty. However, if developers modify the code, they must release the custom software back into the community under the GPL.

"I give you a gift of code, you accept the terms of the license," Hansson said.

Automattic's idea that WP Engine is not giving back enough to WordPress is a blatant violation of the pillars of open source. It cannot retroactively set up a series of "shadow obligations" after a third-party project makes a few bucks on a venture that implements its FOSS code. Otherwise, the GPL becomes "meaningless," and the Free Open Source Software movement loses one of its foremost cornerstones.

That said, Hansson notes that WP Engine is no saint, either. The managed hosting company, owned by private equity firm Silver Lake, partnered with Mullenweg, focusing on technology investments. Before selling its shares to Silver Lake in 2018, Mullenweg's company was part of WP Engine ownership.

Open-source advocates should only care about the integrity of FOSS licenses, and Automattic can adopt a different license for their code whenever they wish. However, Hansson thinks it will likely keep fighting for a share of WP Engine's revenue because Mullenweg has clearly shown that he wants to retain the open-source nature of WordPress while extracting his "pound of flesh from any competitor" whenever it suits him.