Modular_Debugger
Modular Debugger
Low-level debugger
The modular debugger (mdb) is an extensible, low-level debugger developed by Sun Microsystems for the Solaris 7 operating system. It is now open sourced, under the Common Development and Distribution License (CDDL).
Its source code is now available in all open source derivatives of Solaris, such as Illumos.[1]