<p>My company has an existing established WinForm application which in running on WinXP.  The application does alot of sound processing using DirectSound.</p>

<p>My company would like to evaluate Mono, as an alternative on a per workstation cost to Vista/Win Server 2008.</p>

<p>I've heard that different estimates, ranging from 'it will work easily on Mono' to 'it could take months of recoding in certain cases to get a WinForm app to run with Mono on Linux'.</p>

<p>Does anyone have a good real world experience with this?
A good link reference?
I would like to get a better idea before I commit to testing.</p>

<p>Thanks!</p>

The WinForms part will be easy, you may have to do very little as Mono now claims to support Winforms 100%, however all the DirectSound calls will have to be rewritten to use an API available on Linux, ALSA being the obvious choice.
I have written small apps in VS 2005 and ported them with ease to Mono. If you do a lot of P/Invokes, then you'll have to take that into account, as those may have to be completely rewritten or rethought.
Also, check out
MOMA
: "The Mono Migration Analyzer (MoMA) tool helps you identify issues you may have when porting your .Net application to Mono. It helps pinpoint platform specific calls (P/Invoke) and areas that are not yet supported by the Mono project."