fandom5k, a multi-fandom gift exchange for fic with a 5,000-word minimum, has
opened sign-ups until April 9th, 11:59PM EDT. The schedule and info can be found
here.
het_bigbang remains open for author sign-ups until April 1st and Creator sign-ups until July.

allbingo is hosting a
Untranslateable Words Bingo Fest all month. You can use one of their pre-made bingo cards or make your own.
3weeks4dreamwidth is a way to bring back
three_weeks_for_dw. It will take place on April 25th-May 15th.
holyfuckexchange is an exchange run through AO3 for sexual or romantic content involving at least one deity and is
open for nominations until April 1st, 11:59PM UTC. More info
this way.
whenisitdue is a comm for keeping track of upcoming fandom event due dates.
1word1day is a word-a-day-comm.