Here’s a list of the currently ongoing competitions I’m aware of.
Please edit it to add any competition I’ve missed.
Sorted by next actionable date:
10th Muse 2020 Interactive Fiction Writing Contest
Entry deadline: February 16th
Second Quadrennial Ryan Veeder Exposition for Good Interactive Fiction
Part 2 entry deadline: February 20th
Intent deadline: March 1st
Treasure Hunt Jam
Entry deadline: March 4th
Emily Short Anniversary Contest
Entry deadline: March 24th
Infocom Tribute Jam
Entry deadline: April 15th
Intent deadline: September 1st