Have you ever struggled with the mass of .jar files that you can find in a directory of Java libraries? You have no idea what version each of them is and what its dependencies are. You want to put your own application jar in there, but you know that will mean needing to get hold of 20 other jar files to deal with its dependencies.
Sonatype Nexus is a repository for build artifacts, which is particularly handy if you have a Maven project. Once you have your Maven project configured, every time you run
mvn deploy Maven will do a bit of building and then upload the resulting artifacts (.jar, .war, …) to the repository. If you browse Nexus you will then be able to find those artifacts with a unique name and download them.
This is all great, but if your project is running on a snapshot version, then every time you deploy to Nexus, the artifact file name will be appended with date and an ever-incrementing number. For my purposes, I wanted to be able to go on to a Linux test server where I have Apache Tomcat installed and grab the latest .war file. Maybe I need to relax more, but I was getting a bit irritated with having to manually find the snapshot in Nexus, copy the link and then fire off a
curl -O -L http://... command every time I updated the project.