Competition is the mother of invention. After SQL AOP was invented, Cameron quickly came out with A-SQL. Both projects have common goals (bringing AO to the DB world), but we have different philosophies.
So, I quickly realised that some of the concepts that were placed in SQL AOP also fit nicely with XML. I have to give some of the credit to Hibernate 3, which has been called an ORXM rather than just an ORM.
I want the ability to modularize my XML cross cutting concerns, just like I do with my SQL ones. Luckily, we have great features such as Schema to help me out. Anyone who has worked with ref’d in XML can attest to this.
In fact, I have started to eat my own dog food here. Instead of using <preGoal> with Maven, I am using <before> SQXML advice.
I also feel that with SQXML AOP, we do not have the need for SDO, as this merger of SQL and XML can handle Web Services automatically.
Take that Cameron :)