International Business Machines Corporation (IBM) — includes products from the former Rational Software Corporation

IBM (International Business Machines Corporation) is a global technology and consulting company founded in the early 20th century that provides hardware, software, cloud and AI services to enterprises. In 2003 IBM acquired Rational Software Corporation, bringing Rational's suite of software development and lifecycle tools into IBM's software organization. Those products have historically been marketed under the IBM Rational brand and, more recently, under IBM Engineering and IBM Software umbrella offerings.

The Rational lineage includes development and application lifecycle management tools such as Rational ClearCase (including ClearCase Explorer), ClearQuest, Rational Rose, Rhapsody and requirements-management offerings (e.g., DOORS/DOORS Next). These tools are used for version control, configuration management, modeling, requirements management and broader ALM/ELM workflows in large enterprises, especially in regulated industries. IBM also maintains a significant open-source and dev...