WW I online

What are some of this groups favorite WW I websites? I would hate to be missing out on something.

Here's a link to the WWI Poetry Digital Archive, Railsplitter:

http://www.oucs.ox.ac.uk/ww1lit/

If I can remember other WWI sites I've visited, I'll add them here. Does anyone else know of interesting WWI websites?

Not a war-specific site, but Teresa Nielsen Hayden does an annual post at Making Light with many links to WWI sites. The 2013 iteration.