WebSphere Application Server Liberty overview

Liberty is a highly composable, fast to start, dynamic application server runtime environment.

You can install the server as described in Installing Liberty by using downloaded archives.

Because Liberty does not include a Java™ runtime environment (JRE), you must install a compliant Java implementation (JRE or SDK) beforehand. For more information about supported Java environments and where to get them, see Minimum supported Java levels.

This server supports two models of application deployment:
  • Deploy an application by dropping it into the dropins directory.
  • Deploy an application by adding it to the server configuration file.
Liberty supports a subset of the following parts of the full WebSphere® Application Server programming model:
  • Web applications
  • OSGi applications
  • Enterprise JavaBeans (EJB) applications
Associated services such as transactions and security are available to these application types.

Features are the units of functionality by which you control the pieces of the runtime environment that are loaded into a particular server. For a list of the main Liberty features, see Liberty features. You can also create your own features, as described in Extending Liberty.

You can work with the runtime environment directly, or use the WebSphere Application Server Developer Tools for Eclipse. Further, you can use Admin Center to administer Liberty servers and applications and other resources from a web browser. See Administering Liberty.

On distributed platforms, Liberty provides both a development and an operational environment. On Mac OS, it provides a development environment.

For z/OS platforms On z/OS systems, Liberty provides an operations environment. You can work natively with this environment by using the MVS™ console. For application development, consider using the Eclipse-based developer tools on a separate distributed system, or on Mac OS.

You can organize Liberty servers into collectives to support clustering, administration, and other operations that act on multiple Liberty servers at a time in order to efficiently and accurately deliver application services to your organization. See Collective architecture for more information.