The Booch method is one of the earliest object-oriented analysis and design methods.
When it was first developed in the late 80's, the method was geared towards ADA 
implementation.  There were criticisms that the method did not truly support object-oriented
features.  However, the method was revised in the early 90s to provide full support to 
object-oriented analysis and design.  The latest revision of the method has absorbed
ideas from other popular OOA&D methods such as OMT and OOSE.

Recommended reading:

Object-Oriented Analysis and Design with Application by Grady Booch. 2nd Ed.
The Benjamin/Cummings Publishing Company, Inc.