This is the new pre-realease Minecraft 1.7.4 that has been fixed some crash errors and bugs from the previous version. You can start downloading it now for free in this website.
As I said above, in this version, you can stream you game via Twitch by just one click, very easy and quickly! First, you need to visit this page and link your Twitch account to your Mojang account. Then you can use F6 button while ingame to start streaming. You can setting and modify your video quality inOptions -> Broadcast Options. This steam feature just support Windows and Mac OSX, you cant use this feature in other platform!
Minecraft 1.7.4 for multiplayer server: minecraft_server.1.7.4.exe Enjoy!