Beta Test

"Beta" is a nickname for software which has passed the alpha testing stage of development and has been released to users for software testing before its official release. It is the prototype of the software that is released to the public. Beta testing allows the software to undergo usability testing with users who provide feedback, so that any malfunctions these users find in the software can be reported to the developers and fixed. Beta software can be unstable and could cause crashes or data loss.

In League of Legends it was initiated since April 2009, and it is still in development