[Mono-list] web services w/ attachments

[Ben Anderson]

Hi,
I'm involved in a project where we need to develop a server which
hosts webservices (w/ support for attachments).  We are mainly a java
shop, so that's the platforma the server will run on.  We most likely
will need to interop with a dotnet client.  I've gone through this
process before (writing java on the server and dotent for the client)
except not with attachments.  We're pretty open as far as the
specifics go - whether it's rest, soap, or whatever.  We may even go
the option of divorcing the webservices from the sending of files. 
For instance - maybe just upload a file (in a typical multipart-form
http request) and then call a web service to complement the uploaded
file.  I've done similar things in java using Apache's httpclient api.
 I guess I'm wondering if there are any good free c# libraries for
sending http calls, or doing rest, or doing soap beyond what m$oft
offers (looks like dime is the only attachment support?).  I'm
somewhat familiar with C# but am a complete outsider as far as the
community goes.  I really don't care how we do it in on the server in
java (there's enough tools to make it rather simple).  So we want to
pick whatever's easiest to interop with c#.  It doesn't have to be
straightforward either.  Any links to projects or documentation would
be great.
Thanks,
Ben