Known as a major contributor to UML, Objectory, RUP, and aspect-oriented development, Jacobson has shaped modern software engineering practice. After university, he started working at Ericsson until April 1987, when he started Objective Systems. A majority stake of the company was acquired by Ericsson in 1991, and the company was renamed Objectory AB. Jacobson developed the software process OOSE at Objectory circa 1992.
In November 2005, Jacobson announced the Essential Unified Process, or "EssUP" for short. EssUP was a new "Practice"-centric software development process that stood on the shoulders of modern but established software development best practice. It was a fresh start, integrating successful practices sourced from the three leading process camps: the unified process camp, the agile software development camp, and the process improvement camp. Each one of them contributed different capabilities: structure, agility, and process improvement.
