Okta is a single sign-on technology that is used by many organizations. After using Okta to sign in once, you are then able to access a wide range of services (mail, calendar, git, etc.) without needing to sign in again.
Okta is hosting a hackathon to use a new version of their product.
"Your mission, should you choose to accept it, is to use the new Okta Identity Engine Limited GA release to build a working app (SPA, server-side, or mobile) using the Okta Identity Engine developer platform. Build on your own or in teams of no more than 4 people."
$20k in prizes, including $1,900 for being the most helpful to people during the hackathon. Deadline September 14.