There are several systems/databases at the back. I want to be able to store data from them as XML files which can be updated whenever data in those back dbs changes (I can do that with triggers etc - so that shouldnot be a problem). I want to use these XML files to access the information rather than accessing the databases. This access will be using something like a browser based portal.

So would I need some expensive XML engine to search and access infor in these XML files or is there another way to do that?

Also - is there a threshold above which it is necessary to use the expensive tools like those by WebMethods etc...

Thank you,