Mono core library (for CLI 2.0) 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. This package contains the Core Library (mscorlib.dll) of Mono for CLI 2.0, which is the glue between the BCL (Base Class Libraries) and the JIT. You should install libmono-i18n-west2.0-cil if you are using ISO 8859-15 (Latin 9) or other common Western European code pages. US-ASCII, ISO 8859-1 (Latin 1) and UTF-8 users don't need any extra I18N packages.