Many of the modules live in the OpenACS 4.6 toolkit itself, dotLRN is an add-on that leverages the toolkit with a custom portal-based user interface. If you click on the "download" link at the top of each page on this site you'll see that the OpenACS 4.6.1 Beta 2 tarball is available for downloading (it is about to become non-beta so if you don't find it, just download the final 4.6.1 tarball)
You'll find survey, in particular, in that tarball. You need to copy your dotLRN modules to the packages subdirectory in your OpenACS 4.6.1 install directory. We'll be cleaning this up when we release the first dotLRN 1.0 beta in the next couple of weeks (we hope)
As far as functionality goes, the events and research collaboration packages aren't released at this time but the rest is there.
