Hi Luis! One idea occured to me today: I don't know how easy it would
be to do, but looking at wstest home page, it might be doable,
depending on how tightly coupled it is with soap and/or xml.

Anyway: I don't know if you are familiar with json, or the fastest
java json processor, Jackson (http://jackson.codehaus.org). I wrote
Jackson based on my experiences on Woodstox and Aalto, so it is rather
fast as well. In fact, slightly faster than Aalto for most cases,
although that's mostly due to json/xml differences.

But more interesting than just json reading or writing, Jackson
package also implements full data-binding support (via ObjectMapper
class); essentially subset of JAXB functionality (and similar to
JibX).
Subset because there is no standard schema language for json, so
code-first approach is supported.
Object deserialization works like:

MyBean bean = new ObjectMapper().readValue(new StringReader("{
\"count\" : 1, \"name\" : \"jackson\" ]", MyBean.class);

and serialization similarly

new ObjectMapper().writeValue(new FileWriter("result.json"), anyValueObject);

(these are using convenience methods, there are full methods too that
allow using of JsonParser, JsonGenerator etc)

Given above, it might be quite easy to implement json-based web
service, where data binding is done using Jackson instead of JAXB. I
would expect such a service to be still faster than Jibx

What do you think?

-+ Tatu +-