Captain Chaos - Neo-Anarchist, moderator for Shadowland during mid-1st edition, I think. (the original moderator just posted as Sys0p, IIRC). Not much is actually known about Cap outside fo his duties with Shadowland. He was given an encrypted program call "JackBNimble" in Dunklezahn's will. He died during Crash 2.0, but the JackBNimble program activated and may have "Saved" a backup copy of Cap. this is just a rumor at this time.
Fastjack - One of the oldest and most skilled deckers, Jack was born in 1999, and during the Awakening received a message on his old Mac Firestorm computer from someone named Saelatra that said "Good morning world. Welcome back. Play nice." What or who Saelatra is has never been revealed. Jack got used as a rules example a bunch in the 1st edition core rulebook. He invented the Attack Program "Jackhammer". He's rarely seen in the flesh, and his matrix icon is a human male figure that's constantly "blurred" so that none of it's features are recognizable. After the Crash 2.0 and the death of Captain Chaos and Shadowland, he gathered a group of interesting runners (and a few non-runners) and started up Jackpoint. he may have a daughter named Perri, who runs the shadows as Skald.
Dodger -- Dodger is a bit more complicated, since Dodger featured heavily in a bunch of early SR novels and later ina couple plotlines. Dodger is an elven decker who took his name from the Charles Dickens' novel Oliver Twist (and often speaks witha bit of archaic old English). He was part of a runner team with an ork named Kham, a mage named Sally Tsung, a street samurai named Ghost Who Walks Inside, and later a decker/shaman named Sam Verner (Who Dodger names Twist). Dodger discovered an AI hidden in Renraku's Seattle mainframe named Morgan and fell in love with it. Renraku captured Morgan, but Dodger rescued her, but she was damaged by Renraku dissecting her code to figure out how she worked. Dodger and Morgan (Now calling herself Magaera) ended up fighting against Renraku and later Deus. I'm not certain of Dodger's 4th edition status off hand, as I don't think he's been mentioned.
hatchetman - Hatchetman was a street samurai and regular Shadowland poster. He is featured in the In Game fiction for the 2nd edition SR book Cybertechnology where he gets implants and becomes one of th first Cyberzombies. It is generally assumed that he is long since dead, as Cyberzombies don't have a long life expectancy in the first place and the 1st generation 'zombies were even worse (6 months to a year at best).