Cove has announced that they've been acquihired by Microsoft:
If you were a Cove user:
What this means for Cove
As part of this transition, the entire Cove team has accepted offers to join Microsoft, and the Cove product will be wound down on April 1. Existing users can continue using Cove until then, but we are no longer accepting new sign-ups.
We've built a data export feature so you can take your work with you. We recommend exporting as soon as possible all user data will be permanently deleted on April 1.
To export your data:
Sign in to your Cove account and go to your Account page.
Click the Export button.
You'll receive an email with a download link when your export is ready. The export will be a ZIP of HTML files containing all spaces you've created.
To export spaces created by others and shared with you, export each of those spaces individually.