This morning I'm in a tutorial by Odysseas Pentakalos (Chief Technology Officer, SYSNET International) on Web Services development with the Apache Web services toolkit. Note that there isn't really anything on the Apache site called the Web services toolkit. Rather, there is a collection of projects for managing various parts of the Web services stack and some WS-* protocols. Ironically, given that this is OSCON, Odysseas is the author of the Windows 2000 Performance Guide.
Axis is the Apache SOAP server. The current version is 1.2 and version 2.0 is in the works. One of the primary goals for 2.0 is enhanced performance. Axis has a standalone server that's intended for testing--not production. The primary server runs as a servlet inside some other servlet container. Axis has support for WSDL 1.1.
One of the primary features of Axis is the extensible type mapping system that provides support for all basic data types and also does automatic serialization/deserialization of Java Beans. Developers can customize the serialization/deserialization with their own classes.