In the Java/Maven ecosystem there are many repositories that publish JARs publicly. This is an up-to-date list of the ones that you are likely to encounter.

Maven Central

What is Maven Central?

Maven Central, a.k.a. the Central Repository, is the default repository for Maven, SBT, Leiningen, and many other JVM based build tools. It has been around since 2002, and serves many terabytes of assets every year. Maven Central also has a search site.

Where is the Maven Central repository?

Maven Central can be accessed from https://repo.maven.apache.org/maven2/.

Sonatype Releases

What is Sonatype Releases?

The Sonatype Releases Repository, a.k.a. OSSRH, is used as a staging repository to promote releases to Maven Central. If you want to publish to Maven Central, you will need to go through here. However you are unlikely to need to depend on it directly for your repositories.

Where is the Sonatype Releases repository?

Sonatype Releases can be accessed from https://oss.sonatype.org/content/repositories/releases/

JCenter

What is JCenter?

JCenter is a superset of Maven Central, served by Bintray. It contains everything in Maven Central, as well as projects that are published directly to JCenter. It is the default repository in Android Studio and Groovy Grape. You can see some comparisons betwen JCenter and Bintray on Stack Overflow and Paresh Mayani’s blog.

Where is the JCenter repository?

JCenter can be accessed from https://jcenter.bintray.com. If you are using Gradle, it has JCenter built in by default, so you can simply replace mavenCentral() with jcenter().

JBoss

What is the JBoss repository?

The JBoss Maven repository provides artifacts built by the JBoss community. There are several repositories to choose depending on your needs, see the MavenRepositoryFAQ and Maven Repository for more details.

Where is the JBoss Maven repository?

The main releases repository is available at https://repository.jboss.org/nexus/content/repositories/releases/

Clojars

What is Clojars?

Clojars is the community maintained Maven repository for open source Clojure libraries. It is open source and has a lower barrier of entry to publishing than Maven Central. Clojars is backed by a CDN provided by Fastly to ensure fast, reliable delivery.

Where is Clojars’ Repository?

Clojars can be accessed from https://repo.clojars.org

Atlassian Maven

What is the Atlassian Maven Repository?

Atlassian Maven supplies artifacts for Atlassian Plugin Developers. You should use the Atlassian Plugin SDK to ensure your settings are always up to date. Previously packages were available from maven.atlassian.com, but this is now deprecated.

Where is Atlassian’s Maven Repository?

Atlassian Maven releases can be accessed from https://packages.atlassian.com/maven/public, and snapshots from https://packages.atlassian.com/maven/public-snapshot. You can also use the Atlassian Maven Proxy which provides Atlassian packages, as well as proxying Maven Central.

Oracle Maven

What is the Oracle Maven Repository?

The Oracle Maven Repository provides access to Oracle’s JARs. To access them, you need to register. Among other products, they provide JARs for Oracle Fusion Middleware, and Oracle JDBC drivers.

Where is Oracle’s Maven Repository?

The Oracle Maven Repository can be accessed from https://maven.oracle.com after registration.

Google’s Android Maven Repository

What is the Google Android Maven repository?

Google’s Maven repository is mostly used for distributing artifacts relating to Android. Google’s open source Java libraries like Guava and gRPC are published to Maven Central.

Where is Google’s Android Maven repository?

Google’s Maven repository can be accessed from https://maven.google.com (an alternative URL is https://dl.google.com/dl/android/maven2/). If you are using Gradle 4.1 or higher, you can use it by adding google() to your repositories configuration in your build.gradle file.

Google’s Mirror of Maven Central

What is the Google Maven Repository Mirror?

Google Maven Central is a mirror of Maven Central hosted on Google Cloud Storage. If you are downloading Maven artifacts from within Google Cloud Platform, Google’s mirror may provide a substantial speedup. You can find more details from Jason van Zyl’s blog post or Google’s announcement.

Where is Google’s Maven Repository Mirror?

The Google Maven Repository is available from three regional mirrors:

America

<settings>
  <mirrors>
    <mirror>
      <id>google-maven-central</id>
      <name>GCS Maven Central mirror</name>
      <url>https://maven-central.storage-download.googleapis.com/repos/central/data/</url>
      <mirrorOf>central</mirrorOf>
    </mirror>
  </mirrors>
</settings>

Europe

<settings>
  <mirrors>
    <mirror>
      <id>google-maven-central</id>
      <name>GCS Maven Central mirror EU</name>
      <url>https://maven-central-eu.storage-download.googleapis.com/repos/central/data/</url>
      <mirrorOf>central</mirrorOf>
    </mirror>
  </mirrors>
</settings>

Asia Pacific

<settings>
  <mirrors>
    <mirror>
      <id>google-maven-central</id>
      <name>GCS Maven Central mirror Asia Pacific</name>
      <url>https://maven-central-asia.storage-download.googleapis.com/repos/central/data/</url>
      <mirrorOf>central</mirrorOf>
    </mirror>
  </mirrors>
</settings>

Clojure (dead)

What is the Clojure repository?

The Clojure repository (not to be confused with Clojars) was a repository that stored early versions of Clojure, Clojure-Contrib, and various other Clojure related projects. In 2016 it was accidentally killed during an upgrade. Most of the important JARs were already available on Maven Central, so this caused very few issues, and those few issues had the artifacts in question uploaded to Maven Central. In the unlikely event that a project you are using is missing a dependency that was provided by the Clojure repository, then Alex Miller has a full backup of the repository.

Where is the Clojure repository?

The Clojure repository was available at https://build.clojure.org, but it no longer runs a Maven repository.