According to the Stack Comparison on the Apache Web Services Wiki, currently Apaches Axis 1.x and Axis2, Metro@GlassFish, and Oracle Application Server 10g provide asynchrony on the client and server.
Apache Axis2 is an open-source web services engine which allows for the invocation and implementation of web services using Java or C. One of the key features of Axis2 is its ability to provide synchronous and asynchronous interactions as explained by Rajith Attapattu,
Support for both asynchronous and synchronous interactions is a key requirement in web services as both styles have strong use-cases. Axis2 provides this flexibility at the transport layer by allowing responses asynchronously via the same transport or via a different transport. For example, if a request comes via HTTP and the processing is done asynchronously, the reply can be sent via HTTP or it could leverage a completely different transport, such as JMS.
