I was recently asked on Twitter about the status of the fourth edition of CSS: The Definitive Guide. A fair question, given how long the project has lain dormant! I have two things to announce on that front.
The first is that I'm really excited to say that Estelle Weyl has joined me as co-author for the fourth edition. We're working in parallel, tackling individual chapters and doing technical review of each other as we work. Sharing the load, especially with someone as sharp and knowledgable as Estelle, will help get chapters out faster, and the overall book done sooner.
The second is that writing is once again underway, with four chapters in process. I've got the transforms chapter done, and the backgrounds and gradients (and maybe foreground colors too) chapter almost done. Estelle is nearing the end of transitions and animations, with flexbox up next. What comes after that for each of us is a little bit up in the air, though I'll probably tackle basic visual formatting next. Unless I get distracted by something more interesting, of course—truth be told, I've been eyeing grid layout with some covetousness in my heart.
So, the book is once again underway, and actually has been for a little while now. I can't say with certainty when we'll be done and ready to compile everything into the Doorstop Edition, but we're pushing for this year or early next.
As an offshoot of this renewed push, I've been expanding and revising my CSS test files so that I can check my understanding of the specification, as well as test the fine details of browser support. Over the holidays I decided, more or less on a whim, to commit the whole kit 'n' kaboodle to Github. There's no license and no readme, mostly because I didn't think to establish either when I set up the repository. Sorry, I guess? In any case, I regard the CSS in the tests to be public domain, but the actual content (whether inline or replaced) of the HTML files may or may not be, so a single license would have been hard to assert anyway. I mostly put the files up there as a form of open backup, and also to smooth out the process of managing updates to the tests between my local machine and meyerweb. Feel free to make use of the tests for your personal ed ucation, though!