There are several websites associated with this one. These are for different aspects of the work we do. The separate websites provide specific focus for the topic represented.
Probably the oldest and largest research project in requirements engineering was the ISDOS project at the University of Michigan. Its most widely used and known product was PSL/PSA.
The intellectual origin of almost all systems analysis techniques, relational theory, and object-oriented thinking is the philosopher Rudolf Carnap. Many analytical approaches can be seen as derived from Carnap's constructor principles, resulting in discussion about models, metamodels, and metametamodels. There is discussion about this at the website devoted to metametamodelling (and languages). This topic is key for requirements engineering whether the target system to be developed is computer-based, or much wider (and could be a system that involves no computers).
Other websites are for books: (1) Business Process Analysis: including Architecture, Engineering, Management, and Maturity, (2) Emotional Abuse in the Classroom: the forgotten dimension of safeguarding, child protection, and safer recruitment, and, (3) Nuclear Weapons and International Law. Each book has its own website.
The book Nuclear Weapons and International Law has been published under the new imprint Peace Analytics which will soon have its own website.