[Solarsail]

Well, scriptcs sounds somewhat analogous. Similar REPL for C#, allows for packaged scripts, plays nicer with the filesystem than an IDE (which you'd expect for command-line apps). http://scriptcs.net/

Note: I've tried to use scriptcs, but the extent of my C# knowledge consists of pretending it's Java. But people do seem to compare it to LINQPad, so maybe it fits.

[shakna]

Linqpad's amazing "dump" isn't to be found in scriptcs or anywhere else, so far as I'm aware, however. Which really does make working with a C# REPL a million times nicer.