According to MoMa, the only issues are that Mono does not support OracleParameterCollection.AddWithValue, so our Oracle provider will not work, nor does it support ConfigurationManager.get_ConnectionStrings(). Therefore, you cannot put our EntitySpaces configuration sections in an app/web config file. You will need to use EntitySpaces configless mode, as noted in this Blog post.
I have not used Mono myself, but there are no issues reported in our ES2008 .NET 2.0 SqlClientProvider runtime, so I think it should be possible without FreeTDS.
David Neal Parsons
www.entityspaces.net