NO LONGER BEING UPDATED - ONGOING THINGS 'N' SHIT BELOW
Weekly prompts: Apocalypse-writing House-of-Playwrights TheWritersMeow
theWrittenRevolution posts monthly prompts.
Eastern Poetry Forms at the-haiku-club so ffs you no longer have an excuse to call a senryu a haiku.
Need to ask an expert questions for your project, or have a skillset to offer? TheKnow!
Publishing Resources by SadisticIceCream
Persistent-Practice has been prolific with posts.
ScreamPrompts is chock full of awesome, challenging prompts.