new “Practice”-centric software development process derived from established software development practices. It integrated practices sourced from three different 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. Ivar has described EssUP as a "super light and agile" RUP. IJI have integrated EssUP into Microsoft Visual Studio Team System and Eclipse. EssWork Standing on the experience of EssUP Ivar and his team, in particular Ian Spence and Pan Wei Ng, developed EssWork starting in 2006. EssWork is a framework for working with methods. It is based on a kernel of universal elements always prevalent in software development endeavors. On top of the kernel some fifteen practices have been defined. A team can create their own method by composing practices. SEMAT and Essence In November 2009, Jacobson, Bertrand Meyer and Richard Soley ("the Troika") started an initiative called SEMAT (Software Engineering Method and Theory) to seek to develop a rigorous, theoretically basis for software engineering practice, and to promote its wide adoption by industry and academia. SEMAT has been inspired by the work at IJI, but with a fresh new start. It has resulted in Essence, which is an OMG standard since November 2014. Essence views methods as a combination of software engineering and development practices. It aims to enable the abstraction of practices from the methods, thus facilitating their reuse and combination for tailoring methods as best suits the needs. Publications Jacobson has published several books and articles, a selection: 1992. Object-Oriented Software Engineering: A Use Case Driven Approach (ACM Press) With Magnus Christerson, Patrik Jonsson & Gunnar Overgaard. Addison-Wesley, 1992, 1994. The Object Advantage: Business Process Reengineering With Object Technology (ACM Press). With M. Ericsson & A. Jacobson. Addison-Wesley, 1997. Software Reuse: Architecture, Process, and Organization for Business Success (ACM Press). With Martin Griss & Patrik Jonsson. Addison-Wesley, 1997, 1999. The Unified Software Development Process. With Grady Booch & James Rumbaugh. Addison-Wesley Professional, 1999, 2004. The Unified Modeling Language Reference Manual (2nd Edition). With Grady Booch & James Rumbaugh. Addison-Wesley Professional, 2004, 2004. Aspect-Oriented Software Development With Use Cases (Addison-Wesley Object Technology Series). With Pan-Wei Ng. Addison-Wesley, 2005. The Unified Modeling Language User Guide (2nd Edition). With Grady Booch & James Rumbaugh. Addison-Wesley Professional, 2005, 2013. The Essence of Software Engineering - Applying the SEMAT Kernel. With Pan-Wei Ng, Paul Mc