This is sdb-cli, a command line interface to the Mono ECMA CLI runtime's soft debugger. It's useful when you want to debug a program without installing a full-blown GUI debugger like MonoDevelop, or when debugging a command line application.
The interface is similar to .NET's MDbg tool as well as GDB, albeit with some differences in syntax.
Please see the INSTALL file for installation instructions.
Please see the LICENSE file for licensing information.