Who is "Quietust"?
He's a human male who, among other things, is interested in the way the 8-bit Nintendo Entertainment System works.
What sort of stuff has he done?
All sorts of stuff.
Long ago, he released the 7th version of a mIRC script called "ircN".
Later, he and a friend took a poorly coded web-based strategy game, rewrote it completely, and released it as "QM Promisance". Years later, once he actually knew how to code in PHP "properly", he rewrote it from scratch yet again, making it more extensible and also resistant to attack.
Somewhere along the line, he took the remains of a half-written NES emulator (called NinthStar), rewrote it completely, and released Nintendulator. It is still under development, but updates are very infrequent (and actual releases tend to be many years apart).
Later, he traced high-resolution photographs of the NTSC NES CPU and PPU, converted them into netlists, then combined it with code from the Visual6502 project in order to create the Visual 2A03 and Visual 2C02.
He's also make significant contributions to "DFHack", a memory modification library written for the game Dwarf Fortress, both by reverse-engineering the game's data structures and writing plugins to do special things with them.
Long ago, he released the 7th version of a mIRC script called "ircN".
Later, he and a friend took a poorly coded web-based strategy game, rewrote it completely, and released it as "QM Promisance". Years later, once he actually knew how to code in PHP "properly", he rewrote it from scratch yet again, making it more extensible and also resistant to attack.
Somewhere along the line, he took the remains of a half-written NES emulator (called NinthStar), rewrote it completely, and released Nintendulator. It is still under development, but updates are very infrequent (and actual releases tend to be many years apart).
Later, he traced high-resolution photographs of the NTSC NES CPU and PPU, converted them into netlists, then combined it with code from the Visual6502 project in order to create the Visual 2A03 and Visual 2C02.
He's also make significant contributions to "DFHack", a memory modification library written for the game Dwarf Fortress, both by reverse-engineering the game's data structures and writing plugins to do special things with them.
Has he ever written anything completely from scratch?
A few things, but not of much interest.
Has he done any timeattacks on this site?
He once did a speedrun of Sonic the Hedgehog 2 which somehow managed to earn a star, though it was quickly obsoleted using a variety of obvious shortcuts which he somehow didn't notice. Given the extreme level of perfection that has come to be expected here, he is unlikely to ever try speedrunning again.
So, what else does he do here?
Not particularly much. He occasionally posts on the forums, but usually doesn't have the time. He rarely even manages to update this page, leaving it outdated for years on end.
Where can I contact this 'Quietust' person?
Your best bet is probably to email him - he has a Gmail account with the username "quietust", and its spam filter probably won't delete your message.
He rarely idles on irc.libera.chat in #tasvideos as "_Q", but he typically doesn't have much to say. He can also be found in #dfhack and #nethack (on the same network), the #nesdev channel on EFnet (and its associated Discord server), as well as on various other discussion forums (such as NESdev, The Daily WTF and Bay 12 Games).
Anything else?
He spends his spare time reverse-engineering Dwarf Fortress, playing various old games (such as Minecraft and Diablo 2 non-Resurrected), and watching animes.