Andrew,

I'm using MM.NET on a big project where I'm also using Crystal Reports heavily. I mainly use MM.NET for data access. I've had no problems with integration. A typical scenario for me is the following:

1) I design a typed dataset in VS.NET
2) I use that typed DS as the data definition for my report, as well as the result set from SQL Server.
3) I bring back the data from a SQL stored proc, using the MM.NET SP functions
4) I bring the result set contents to the report and generate the report.

I'm not a Mere Mortals "expert", but to the best of my awareness, MM.NET doesn't "support or not support" Crystal any more/any less than any other report writer. My use of Crystal is basically beyond the realm of the MM framework. (Kevin M. can come in and correct me if there's any specific support for a report writer in MM).

I recently saw some stats: Crystal has roughly 49% of the developer market as a reporting tool, with ActiveReports coming in 2nd at something like 25 or 29% (I forget the exact stats). Crystal has its quirks, but generally I believe it's the best overall reporting tool for .NET.

Hope this helps...
Kevin