ben@ben1520:~> csharp
Mono C# Shell, type "help;" for help

Enter statements below.
csharp> Environment.Version;
4.0.30319.1
csharp> Environment.OSVersion;
Unix 2.6.34.7
csharp> var pi = Math.PI;
csharp> pi / 2;
1.5707963267949
csharp> ShowVars();
double pi = 3.14159265358979
csharp> quit;
ben@ben1520:~> 

ben@ben1520:~> csharp
Mono C# Shell, type "help;" for help

Enter statements below.
csharp> help;
"Static methods:
  Describe (object)       - Describes the object's type
  LoadPackage (package);  - Loads the given Package (like -pkg:FILE)
  LoadAssembly (assembly) - Loads the given assembly (like -r:ASSEMBLY)
  ShowVars ();            - Shows defined local variables.
  ShowUsing ();           - Show active using declarations.
  Prompt                  - The prompt used by the C# shell
  ContinuationPrompt      - The prompt for partial input
  Time(() -> { })         - Times the specified code
  quit;                   - You'll never believe it - this quits the repl!
  help;                   - This help text
  TabAtStartCompletes - Whether tab will complete even on emtpy lines
"
csharp> ShowUsing();
using System;
using System.Linq;
using System.Collections.Generic;
using System.Collections;
csharp> quit;
ben@ben1520:~> 

ben@ben1520:~> csharp
Mono C# Shell, type "help;" for help

Enter statements below.
csharp> using System.IO;
csharp> from f in Directory.GetFiles("/etc")
      > let fi = new FileInfo(f)
      > where fi.LastWriteTime > DateTime.Now.AddDays(-7)
      > select f;
{ "/etc/adjtime",  "/etc/fstab", "/etc/group","/etc/mtab", "/etc/passwd", "/etc/shadow" }
csharp> quit;
ben@ben1520:~> 

ben@ben1520:~/work> cat test.cs
using System.Numerics;
var a = 13;
BigInteger.Pow(a, 53);
ben@ben1520:~/work> csharp test.cs -r:System.Numerics.dll
109395050288514219040366056833567359441133418834382438145053
ben@ben1520:~/work> csharp --version
Mono C# compiler version 4.0.0.0
ben@ben1520:~/work>