As I mentioned in a post last week, I have consulting at a client site that uses an Agile Project Management Methodology. As a Project Manager, I had thought that I have not used Agile before, however, I now understand that as a Project Manager / Developer for many years, I have previously been using an Agile methodology.
In my very first job, after leaving university, I was coding a 4GL, and our Project Management Methodology was DSDM (Dynamic Systems Development Methodology). I went on a course and actually became a DSDM Practitioner. This was back in 1997.