mono 1.2.3.1-1ubuntu1 (amd64 binary) in ubuntu feisty

 Mono is a platform for running and developing applications based on the
 ECMA/ISO Standards. Mono is an open source effort led by Novell.
 Mono provides a complete CLR (Common Language Runtime) including compiler and
 runtime, which can produce and execute CIL (Common Intermediate Language)
 bytecode (aka assemblies), and a class library.
 .
 mono is a metapackage containing dependencies for the runtime of Mono.
 If you do not need all of them (or try to work around X11
 dependencies), install the core packages manually: mono-jit, mono-mcs or
 mono-utils.