The legal battle between Automattic and WP Engine over WordPress trademarks continues to escalate. Just days after WP Engine issued a cease-and-desist letter accusing Automattic CEO Matt Mullenweg of defamatory remarks, Automattic has responded with its own cease-and-desist notice. Automattic claims WP Engine has infringed on several WordPress-related trademarks, arguing the company has unfairly capitalized on WordPress branding to build its business.

According to Automattic, WP Engine’s misuse of WordPress trademarks has contributed to misleading consumers into thinking there’s an official affiliation between the two companies. Automattic alleges this confusion has harmed its reputation and demands compensation for profits WP Engine has made by using the WordPress name. The letter warns that if WP Engine doesn’t resolve the matter, Automattic may pursue further legal action.

This dispute started after Mullenweg publicly criticized WP Engine at WordCamp, calling the company a “cancer to WordPress” and accusing it of profiting from the open-source project while contributing little to the community. WP Engine fired back, defending its use of the WordPress name under fair use laws and rejecting what it described as Mullenweg’s “outrageous” financial demands for ongoing trademark use.

As tensions rise, many in the WordPress community worry this legal conflict could damage the open-source ecosystem, where cooperation has traditionally driven growth. The outcome could have lasting implications for companies profiting from WordPress while giving back minimally to the project.