Yahoo sues Mozilla for breach of contract -- so Mozilla countersues Yahoo

Mozilla and Yahoo have started a legal spat about the deal that existed between the two companies regarding the use of the Yahoo search engine in the Firefox browser.

On December 1, Yahoo fired the first shot filing a complaint that alleges Mozilla breached a contract that existed between the two companies by terminating the arrangement early. In a counter complaint, Mozilla says that it was not only justified in terminating the contract early, but that Yahoo Holdings and Oath still have a bill that needs to be settled.

Yahoo's complaint centers on "breach of contract" and "breach of covenant of good faith and fair dealing." Mozilla's counter complaint concerns "declaratory relief," "breach of contract re payments," and "breach of contract re search performance."

As this is an on-going legal battle between the two tech giants, the complaint documents are fairly heavily redacted -- but there's enough still visible to get a good handle on what's going on.

Mozilla terminated the agreement that it had in place with Yahoo in early November, with Yahoo having allegedly ceased payments after the end of October. Mozilla says that it was unhappy with Yahoo search performance, and made a number of suggestions to owners Oath -- suggestions that seemingly were not well-received, as the cross-complaint reveals:

Yahoo Acquirer's response to Mozilla's concerns was in stark contrast to Yahoo's assurances from CEO Mayer at the time the Strategic Agreement was entered into. Yahoo Acquirer's leadership provided no vision, no structured, documented and vetted strategic path forward, and no assurances as to a commitment of the resources necessary to improve Yahoo Search such that it would meet.

Drawing attention to its legal action in a blog post, Mozilla points out that while it is not possible to reveal full details of what is going on, it would like to try to be as transparent as possible. Denelle Dixon shares the company's official statement on the matter:

On December 1, Yahoo Holdings and Oath filed a legal complaint against Mozilla in Santa Clara County court claiming that we improperly terminated our agreement. On December 5, Mozilla filed a cross-complaint seeking to ensure that our rights under our contract with Yahoo are enforced.

We recently exercised our contractual right to terminate our agreement with Yahoo based on a number of factors including doing what's best for our brand, our effort to provide quality web search, and the broader content experience for our users.

Immediately following Yahoo's acquisition, we undertook a lengthy, multi-month process to seek assurances from Yahoo and its acquirers with respect to those factors. When it became clear that continuing to use Yahoo as our default search provider would have a negative impact on all of the above, we exercised our contractual right to terminate the agreement and entered into an agreement with another provider.

The terms of our contract are clear and our post-termination rights under our contract with Yahoo should continue to be enforced. We enter into all of our relationships with a shared goal to deliver a great user experience and further the web as an open platform. No relationship should end this way -- litigation doesn't further any goals for the ecosystem. Still, we are proud of how we conducted our business and product work throughout the relationship, how we handled the termination of the agreement, and we are confident in our legal positions.

We remain focused on the recent launch of Firefox Quantum and our commitment to protecting the internet as a global public resource, especially at a time when user rights like net neutrality and privacy are under attack.