Testing Grounds
Forgecraft for the rest of us
Testing Grounds is a server for mod creators to test their mods in an SMP environment, rather like the Forgecraft series of servers. We are currently accepting whitelist applications until October 31, when the server will be invite-only. To apply, you must be either a mod maker or a YouTube or Twitch partner.
More info and whitelist application: http://classcoder.com/testing-grounds
(The whitelist application doesn't ask for contact info, I will contact you using a MC Forums, YouTube, or Twitch PM over the accounts you link to.)