For a recent project, I needed a simple way to be able to re-direct Schema  
locations in a .NET application, i.e. use a local copy of a Schema rather  
than download the Schema from the "schemaLocation" URL in the XML  
document.  The way that I would normally do this is using OASIS XML  
Catalogs  
(http://www.oasis-open.org/committees/download.php/14809/xml-catalogs.html),  
but I couldn't find a suitable .NET implementation.  So, I have written  
one, called "xmlcatalog.net":

http://secure.mileywatts.com/confluence/display/CMSW/Miley+Watts+XML+Catalogs+for+.NET+and+Mono+(xmlcatalog.net)

It's open-source, under the Apache 2.0 licence.  Note that it currently  
doesn't implement a few of XML Catalogs features that relate to DTDs  
rather than W3C XML Schemas.  I don't know how many people are actually  
doing DTDs under .NET or Mono; if you need DTD support, please register  
(there is a link at the download site) and post an issue about it (or add  
a comment to an existing issue, as appropriate).

I want to support Mono as well as .NET, but as yet it isn't tested with  
Mono due to some NUnit issues under Mono on openSUSE 10.3.  I plan to have  
it tested for Mono as well before too long.

I hope some of you will find this useful, and any feedback will be very  
welcome.  Thanks a lot in advance,

Cheers, Tony.
-- 
Anthony B. Coates
Senior Partner
Miley Watts LLP
Experts In Data
UK: +44 (20) 8816 7700, US: +1 (239) 344 7700
Mobile/Cell: +44 (79) 0543 9026
Data standards participant: genericode, ISO 20022 (ISO 15022 XML),  
UN/CEFACT, MDDL, FpML, UBL.
http://www.mileywatts.com/