onesongaday is a comm to share music.

50books_poc is a book challenge to read more works by POC.

thebigbangblogproject is a collaborative effort to find any and all fandom challenges and promote them

comment-exchange is a place where you can submit works with no/low interaction to get promoted and in exchange, you have to comment on another work.

fanfic-reading-challenge is running 2024 Fic Reading Challenge.

ficwip is running Hey Sweetheart (link takes you to website not tumblr), a challenge to include the word sweetheart in fic/art, with optional prompts on Feb 11-14th.

seasonofdelightsbingo is running a Spring Delights Bingo. Sign-ups are open until March 15th and posting will run from March 1st-June 30th.

threesentenceficathon is currently ongoing! The second post is open for prompts/fills and first post is still open for fills but not new prompts. :)

goreswap, a multifandom exchange for fanfic and fanart dedicated to gore, is accepting nominations until January 19th, 11:59PM Eastern.

kitarella_imagines is running Funuary and has posted fun themed prompts on AO3 for people to use and then submit those works to the collection.