Apache Axis is an implementation of the SOAP ("Simple Object Access Protocol")
submission to W3C.
From the draft W3C specification: 
SOAP is a lightweight protocol for exchanging structured information in a
decentralized, distributed environment. It is an XML based protocol that
consists of three parts: an envelope that defines a framework for describing
what is in a message and how to process it, a set of encoding rules for
expressing instances of application-defined datatypes, and a convention for
representing remote procedure calls and responses.
This project is a follow-on to the Apache SOAP project.

Apache Axis is licensed under the ASL (Apache Software License) version 2.0
which you can find a copy of in ASL-2.0-License.txt or at
http://www.apache.org/licenses/LICENSE-2.0.html