The most popular tools for that are: MavenMaven, IvyIvy, GrapeGrape, GradleGradle, BundlrBundlr, SBTSBT, LeiningenLeiningen, but they're keeping dependencies for all projects in one folder. ComposerComposer keeps dependencies inside a project, in a subdirectory.
You can browse content of main Maven repository: http://mvnrepository.com/https://mvnrepository.com/