Moodle 2.9 the upcoming version is ready to get set go for the QA testing as its code freezes on 06 April. The QA testing for Moodle 2.9 will start from 13th of April and after passing all the tests the stable release will be available from 11th of May.
You can also participate in QA testing through this tracker dashboard: https://tracker.moodle.org/secure/Dashboard.jspa?selectPageId=11454
The site which is running the Moodle 2.9 version for testing is http://qa.moodle.net/ and it is updated every hour with the latest fixes for testers to test and do a final check for any problems.
By participating in the QA testing of Moodle latest version, you can also earn a Moodle Testers badge.
Reference: Moodle QA Testing guide