Bungie games never die, but they do live on in websites that use frames. You have been warned.
However, if you're in the mood for a blast from the past, check out the Pathways Into Darkness page at Bungie.org, where Hamish Sinclair, who maintains that page as well as the compendious and excellent Marathon Story Page, has added information on the A1 demo version of Pathways Into Darkness that was released way back in July of 1993 before MacWorld Boston that year.
For those who don't know, Pathways was a precursor to Marathon, a less sophisticated first-person shooter/adventure game in a pseudo three-dimensional world. The latest update to the PID page details the levels and features in that demo that were removed or changed before the game's final release.