Oh, Curah! We hardly knew you. And, some of us knew you not at all, I'm guessing.
Christened in beta just a couple years ago during TechEd 2014, Curah! was Microsoft's vehicle to accumulate curated content from the web. It allowed selected "curators" (I was one) to supply content into categories through links with comments.
A little has eked out over the past few days about a resurgence in a Microsoft platform called Docs.com. The idea behind Docs.com is to allow anyone to publish and collect all types of Office content and anything from the web. Available as an open platform, so it’s easy for others to discover what interests you. So basically just another "curation" platform but this time with the ability to host Office documents.
For those that had a Curah! account, that too has been migrated to Docs.com already. Here's today's email announcement about the switch.
Microsoft promised earlier this year that new Office services would roll out, helping to reinvigorate a suite of products that, though powerful and popular, have become a bit stale in expansion. Docs.com is another step in that direction, following Sway.com and the recently released Sway app for Windows 10. Microsoft has put together additional information about the move and also provided some getting started steps: http://social.technet.microsoft.com/wiki/contents/articles/20643.what-is-curah-and-how-to-get-started.aspx