Steve, David, and I are pleased to announce that a first public version of Active Calculus – Multivariable is now available for download. You can find the file directly at http://gvsu.edu/s/Wb, or from the general Active Calculus site.
If you are interested in the source files, please email me at boelkinm at gvsu dot edu.
Finally, a quick note about the single variable text: at the link from the Active Calculus site above (or directly from http://gvsu.edu/s/xr), the 2015 version with promised corrections and editorial updates is available. Note well: from the “buy this book” link at the download page, the 2015 version is not yet available. I will post here as soon as the print-on-demand 2015 version is available (which I expect to occur within a week).