There a few very good things about maven:
- Archetypes: A kind of start up (base) project (very useful) that a lot of people make. In businesses where you tend to recreate the same kind of stuff over and over, it is extremely practical.
- Dependency management: You really have to try it to love it. Ivy is a good compatible tool too.
- Life cycle management: Without a entire IDE, you can do everything from the command line with maven and by that I mean: compile, package, test, deploy, etc. And its possible to make some step dependent on others. Although I think that the defaults are not the best, this part is customizable.
Additionally, maven can also do some ant stuff.
The downside for me is really about the fact that it is hard to port a project to it. It is best to start from scratch. Also, maven extensively uses plug-ins to do its job, but not everything is perfect in that regard and there aren't plug-ins for everything yet.
