Demo: Rudy Jurjako e1m4-017 (18/08/1998)
Skills needed: straferunning and some coordination
Difficulty: medium, not too many tries needed
Description:
This trick has a story. As you probably know, Yonatan Donner had the speed record of this map with his e1m4-022 (one of the best speedruns ever, I must add.) What I know is based on what he told me...
The first player to discover the trick was Steffen Winterfeldt, who sent his demo to Yonatan, but for some reason this wasn't introduced to COMPET-N. Later, Jonas Feragen (Chrozoron) has discovered the trick. As he was never a COMPET-N player, he sent his demo to Yonatan, who, of course didn't upload it to COMPET-N, as the record time was his own
. Later, Rudy Jurjako discovered the same trick. He somehow sensed the truth in his text file: "I have a hard time believing that I was the first to discover that jump...". Just *one* day later, Ralf Schreivogel also discovered the jump, not knowing of Rudy and the other people. It's not a surprise that Yonatan doesn't really like this trick 
It's an interesting question if id Software know of this use of the ledge or not. UPDATE: Adam Williamson was kind enough to ask this from John Romero, and with his help we got the undeniable truth from Tom Hall himself:
Here's the answer, straight from The Man who mainly designed E1M4, Tom Hall: "Heeeeeeeeeee. Yeah, I'm pretty sure.
But not sure if you can get to it.... it stops before it gets to the stairs now...so I think you'd have to get propelled backward somehow... so long ago though...I totally forgot that this was in episode 1...man, I should play it again...yeah, like I have time..."
So... i think he *did* design it for a shortcut.
John Romero