Tools for your online collaboration

So the winter school in Hejnice ended two weeks ago is long past -- and despite my intentions I did not find the time to blog. This is primarily a sign of the quality of the winter school, both scientifically and socially. I do admit I spent the lunch breaks walking in the beautiful surrounding mountains instead of blogging...

Anyway, on the last evening of the winter school a couple of people gathered together to exchange tools for collaborating via the intertubes. I volunteered -- also with the upcoming third Young Set Theorists meeting in mind -- to make the discussion available online. Of course, the title refers to this wonderful paper by Goldstern and Judah which taught me the little bit of iterated forcing that I know.