Here is a non-exhaustive list of everyone whose work went into creating DFplex and its ancestor, Webfortress. If you'd like to see someone's name on here, please contact an author or send a PR.
white-rabbit
BenLubar
flbr
Paingouin
DaKnig
mifki <pronvit@me.com>
alloyed <alloyed@tfwno.gf>
Dragoon209
Lethosar, who provided much advice.
Hexa, for setting up the first public server.
DFplex also uses tilesets/colorschemes created by the wider DF community, their names can be found in the static/art and static/colors folders respectively