It’s time for an update
To use the Twitch broadcasting you need to link your Mojang account with your Twitch account. This only works with migrated accounts (in other words, if you login using your email address instead of your username, you can use the Twitch integration). The linking is done via the account settings, which can be found here:
To start broadcasting, simply press F6 while playing. You find more options in the menus.
The integration currently only works on Windows Vista or later, and on Mac OS X Lion (10.7) or later.
Download Minecraft.exe. Place it anywhere you want, then run it.
Download Minecraft.dmg. Unpack and place Minecraft in your /Applications folder.
Download minecraft.jar. The jar is executable and might work as-is. If you run into memory issues, try launching it with java -Xmx1024M -Xms512M -cp minecraft.jar net.minecraft.LauncherFrame, also please use Sun’s JVM.
If you want to run the server on any other OS or without GUI it’s a bit more involved. First make sure you can use java from the command line. On Linux and Mac OS X this should already be set up but on Windows you might have to tinker with the PATH environment variable. Download and run minecraft_server.jar with java -Xmx1024M -Xms1024M -jar minecraft_server.jar (Mirror Download) nogui.
Credits: Minecraft Realms Teams