Here's the Clarion Foundation blogpost about it: The 5th Annual Clarion Write-a-thon
Here's the Clarion Writeathon website where you can sign up to write, or sign up to sponsor writers by making a donation.
I'm a Clarion graduate (2007) and it was honestly life-changing for me. It takes years to unpack everything you learn, and a lot of it isn't even about the craft - you learn about the whole writing ecosystem, so to speak. The write-a-thon funds help to keep this workshop alive, and to sponsor writers who wouldn't otherwise be able to attend.
NEW IMPROVED WEBSITE
My friend and Clarionmate Justin Whitney's poured hours of work into revamping the Write-a-thon website. Here's what he says about it:
"The most significant change was to address the chief complaint we've gotten over the years - the actual sponsorship process. On the fast end, you can now pledge toward a writer's goal with no more than 3 clicks (if you're already logged in) and without ever leaving the writer's page. On the slow end, a brand new visitor can sponsor a writer in about 5 clicks and a couple of short forms, again without ever leaving the page. And that includes both a one-time registration and a one-time credit card form (contact info only - no credit card information). After that, the credit card contact info will be prefilled and login will be remembered, so it's even easier. OR, she can skip registration entirely and go straight to payment - I created a way to keep track of visitors who sponsor multiple writers without ever registering, so it doesn't turn into a big mess on the back-end. Everything is integrated with the admin tools I built so that the entire Thon can be run by 2 part-time volunteers.
"Still, other than revamping the entire sponsorship process, the site looks almost the same as last year, albeit a LOT cleaner."
CLARION: The Best Broken Heart You'll Ever Have
Check it out! If you're a writer, sign up! If you can't, but can donate money to sponsor and encourage writers, that's great too. (And if you can do both, so much the better.)
If this post sounds like hard-sell Hurrah Clarion! - it's because I feel that strongly about the workshop. There's a great blogpost from Sam Miller on the Clarion Blog, called The Best Broken Heart You'll Ever Have. Nails it.