Two digital preservation projects of note: the DejaVu browser emulator (via Jill) and Delorie Software's Lynx Viewer (found via someone, but I can't remember who). DejaVu emulates several older web browsers (IE2, Mosaic, Netscape, and even a line-mode browser). Lynx Viewer emulates Lynx, of course. Besides the nostalgia value (I used Lynx exclusively for a while), these are rather useful tools for testing one's backwards-compatibility. I wa spretty pleased with Donut Age's performance in these environments, though it may have convinced me to move to a table-less layout the next time I have time (maybe this summer).
