Back in the second half of the eighties I have been using some agile practices, but we didn't call it agile back then. We regularly pair programmed because my friend and I shared one computer; neither of us wanted to just sit and do nothing. Our workflow also included writing test programs (much like unit tests today).
In the early nineties I read "Managing the Software Process" by Watts Humphrey. This was my first introduction to the CMM. I found many of the concepts valuable, even though, I was working alone. The knowledge presented was applicable to my software engineering work, with the necessary adjustments for a group size of one.
Many years later, after the agile movement got traction, I was surprised that so many people had such strong feelings about the CMM given my positive experiences with it. In time I understood that there were many organizations that got their CMM implementations off track. They focused on paperwork, instead of changing the day-to-day work of practicing software engineers.
After over two decades of CMM & CMMI and over a decade of agile, the software engineering community is realizing that a sensible strategy is to integrate the best of both worlds. A recent paper published on the SEI website by Hillel Glazer, Jeff Dalton, David Anderson, Mike Konrad, Sandy Shrum urges us to do so: CMMI or Agile: Why Not Embrace Both! It seems that I am not the only one thinking so. Scott Ambler wrote a review of the paper at DDJ called: Agile CMMI: Complimentary or Oxymoronic? Read the paper, read Scott's review, and decide for yourself.