Yes. For traditional WAS, you can obtain a no-charge version for development and testing. This variant is called WebSphere Application Server for Developers, and is available for v9.0 and v8.5.5 of WAS.
It should be noted that the Developer edition is intended for use by individual developers on their workstations. You are not permitted to run a shared/centralized server instance of this product. The product FAQ is pretty clear on this:
What exactly is the entitlement provided with the no-charge WebSphere
Application Server for Developers?
The entitlement provided with the
no-charge WebSphere Application Server for Developers is: For each
WebSphere Application Server for Developers license, you are
authorized to install each component of the no-charge WebSphere
Application Server for Developers on a single machine for use by a
single developer for purposes of testing code to confirm that such
code functions as designed. You are not authorized to use copies of
the no-charge WebSphere Application Server for Developers for the
following purposes: testing applications on servers separate from the
developer's machine; or simulating production workloads or testing
scalability of any code, application or system. The no-charge
WebSphere Application Server for Developers cannot be used for to
provide runtime support for production applications.
For WebSphere Liberty, a similar version is available, which is called Liberty Core. This is again a no-charge/no-support edition, but the license allows the use of the server in small-scale test and production environments, which includes shared/centralized instances.
On the development side, you can use the WebSphere Application Server Developer Tools plugin for Eclipse to work with the servers.
WAS Traditional and WAS Liberty are similar in the sense that they offer similar capabilities and compliance to the Java EE platform. Liberty takes the traditional WAS architecture and breaks it down into a pick-and-match model, which allows you to select the features you need. This makes Liberty more flexible, compared to traditional WAS. For a more detailed comparison, see this article.
