After making and installing mono from a tarball (http://download.mono-project.com/sources/mono/), I took the latest version of RazorEngine down from github (https://github.com/Antaris/RazorEngine), compiled using mono's xbuild tool, and then took the version of RazorEngine.dll and System.Web.Razor.dll from the RazorEngine.Core folder and used that within my applications. I removed all instances of System.Web.Helpers, System.Web.Mvc, System.Web.WebPages, WebMatrix, etc as those would have conflicted references.
And RazorEngine is now really horribly strict :( It throws compile exceptions on warnings which is wholly irritating. I'll have to revisit and police every single template and make sure they are compatible.
I also noticed that the new version of xsp4 required me to be in the root folder of the website even though I was setting the root on the command line.
Anyway, glad to see it working again, even if it will be a chore to get it fully compatible. I guess it is balanced out by now being on .Net 4.5 compatible mono.
Update: I've made an adjustment to the RazorEngine code which stops it treating warnings as errors during template compilation.
Modify RazorEngine.Core/Compilation/DirectCompilerServiceBase.cs, Compile method thusly:
var @params = new CompilerParameters
GenerateInMemory = true,
GenerateExecutable = false,
IncludeDebugInformation = false,
CompilerOptions = "/target:library /optimize",
TreatWarningsAsErrors = false,
WarningLevel = 0
Although the default for TreatWarningsAsErrors is false in Mono, I think the default for WarningLevel is -1, which doesn't really mean anything. So this might actually be a Mono porting issue.