I've been using maven for a while, and I often review repositories before selected what version I want to use. I don't entirely understand what the extensions mean.
I know that when I see extensions like -RC1 and -RC2 that means release candidates. When I see a version without an extension, I assume that means a released version. But what does an extension of -M1 or -M2 mean?
Example:
2.8-RC1
2.8
2.8-M1 ??
M1 means Milestone 1, it's a release name, like beta or alpha. RC means Release Candidate.
A milestone means that the application got a huge improvement from the todo list. A release candidate is a release that can be the final release unless some major bugs are found.
To quote the ASF:
Releases that only represent a project milestone and are intended only for bleeding-edge developers working outside the project are called "alpha".
Resources :