From the Sun web site:

The JavaTM Web Services Developer Pack (Java WSDP) is an integrated toolset that in conjunction with the Java platform allows Java developers to build, test and deploy XML applications, Web services, and Web applications. The Java WSDP provides Java standard implementations of existing key Web services standards including WSDL, SOAP, ebXML, and UDDI as well as important Java standard implementations for Web application development such as JavaServer PagesTM (JSPTM) technology pages and the JSP Standard Tag Library. These Java standards allow developers to send and receive SOAP messages, browse and retrieve information in UDDI and ebXML registries, and quickly build and deploy Web applications based on the latest JSP standards.

The Java Web Services Developer Pack v1.0_01 includes the following:

• Java XML Pack which includes the following:
  • Java API for XML Messaging (JAXM) v1.1_01
  • Java API for XML Processing (JAXP) v1.2_01 (with XML Schema support)
  • Java API for XML Registries (JAXR) v1.0_02
  • Java API for XML-based RPC (JAX-RPC) v1.0_01
  • SOAP with Attachments API for Java (SAAJ) v1.1_02
• JavaServer PagesTM Standard Tag Library (JSTL) v1.0.1
• Java WSDP Registry Server v1.0_02
• Web Application Deployment Tool
• Ant Build Tool 1.4.1
• Apache Tomcat 4.1.2 container