In a post to his blog Ivan Enderlin talks about a move that his team at Automattic (the company behind WordPress) made away from using PHPUnit for their application testing over to atoum and some of the reasoning behind it.
[…] This post is a summary about what have been accomplished so far, the achievements, the failures, and the future, focused around manual tests. As the title of this post suggests, we are going to talk about PHPUnit and atoum, which are two PHP test frameworks. This is not a PHPUnit vs. atoum fight. These are observations made for our software, in our context, with our requirements, and our expectations. I think the discussion can be useful for many projects outside Automattic.
He starts off by talking about the state of the project and testing before they made the switch and where they wanted to end up. He mentions the complexity of the code as one reason for the change and his own contributions to the atoum project. He then covers some of the requirements they had for the new testing tool, how atoum met some of these goals and some of the difficulties they faced during the transition.
The post ends with details about some of the positive and negative aspects of the change including increased code testability (good) and issues moving the whole company over to a new testing tool (bad).