So I had a look into the Wordpress version of Designmodo's Startup Framework. How does the framework cater to the containerist idea?
First of all, it's quite similar. What they call blocks is Containerist's container types, in a pre-filled form. You can place blocks on a page, which is quite the same as placing containers on a container stack. You can (then) modify the block's placeholder texts and images. When a block is filled with your content, it appears under 'your blocks', and you can reuse it. I'm not sure what happens if you place such a 'your block' in two places and then start changing its content. That is, maybe placing your block is copying it, maybe referencing.
One of the main differences is that the Startup Framework works as a layout system. When you type in data into a block template, it is stored only in this place, and not as structured data which then is used in other places with different appearance. Thus, this approach is not Content Management, buy layouting with "flat" containers.
Another difference is the fact that you cannot place a container on a different website. The block is bound to the website it is on.
Nice about their framework seems to be the work they put into the front end design and code. I did not test it enough, and of course the design is quite generic (#sameness effect), but at a glance it looks pleasant and has appropriate responsiveness. Thus, this might be quite a powerful Containerist skin.
(cc-by-sa) since 2005 by Konstantin Weiss.