While building javalibs I parsed all pom files from Maven Central and was able to get URLs out ot them. Almost 94 000 unique artifacts have URL (total number of unique artifacts is currently about 110 000). Most URLs have projects from companies like JBoss and Apache software foundation, but there's one project which has most unique artifact URLs (more than 1 500) and it really got my attention: http://www.webjars.org/
WebJars are client-side web libraries (e.g. jQuery & Bootstrap) packaged into JAR (Java Archive) files. How cool is that? No more downloading jQuery, just change pom.xml and it will be automatically downloaded and used in your web application (well, that part takes a little bit more configuration, but it works like a charm).