Java Edition version history/Development versions

Starting in the period between Beta 1.7.3 and Beta 1.8, Mojang publicly releases testing versions of the full update in order to get major feedback, especially for bug reporting, so that the official update is considerably more stable. While these versions were public, they were not auto-installed by the game and are completely optional.

In Beta, these versions went under the tag of "Pre-Release", candidates subject to release for 1.0.0 as "RC#", and post-1.0.0 were given a name under a special syntax (see below).

Weekly builds
Jeb tweeted that the format for the snapshots is "YYwWWx".

YY is the two-digit year, WW is the two-digit week number within the year, and x is a unique identifier, starting with "a," in case there is more than one release per week.

Beta 1.9 Pre-releases
Considered the "Lost Update", a full version under the name "Beta 1.9" never came. Instead, Mojang opted to delay the release of this update until MineCon 2011 and release it under the name "Minecraft 1.0.0". This decision was made after a few development versions tagged as Beta 1.9 were already sent out, so the name Beta 1.9 was kept for all of the development versions in the gap between Beta 1.8.1 and Minecraft 1.0.0, other than the Release Candidates.