I have had two CCR 2000s. I had one of the early very big ones and one of the smaller ones with Inconel spheres. I met Will Smithers for the first time wearing one of the early ones in Cayman. His dismay at the prototype I was diving provided lively discussion between us for years to come.
It was originally designed and built by Dan Wible. After a few years of pouring money into it, he decided to go back to his real job at Boeing.
The electronics were conceptuallized by Dan and he had them built by two different companies. One built the hardware, and the other wrote the software. In the final stages I worked closely with Dan to help him interface with the software guy to get it finished, but that was the extent of my involvement then.
When Dan went back to Boeing (F22 Raptor program) he sold the manufacturing rights to Olympic Submarine. They started a redesign that probably killed the program. It worked with Dan's version, but the Olympic version was plagued with problems and was never successful.
Although there were two deaths on the unit, both of them were very clearly user error. The product stopped shipping because Olympic Submarines went into bankruptcy. It turns out they weren't very good at building submarines either.
Dan got the rights back and we started talking about a new version. He sent me all of the development platforms and source code, but there were some difficult obstacles. The software had been developed on a very old tool chain that was no longer available. And the PC software was developed on another very old tool chain that was no longer available.
It soon became clear that it would be easier and cheaper to start from scratch. At that point I started working on the KISS stuff, and ithe CCR 2000 upgrade just faded away.
At the time, the CCR 2000 was the most sophisticated product on the market. The Cis Lunar had closed its doors, and the CCR 2000 was the only rebreather with integrated decompression. Like the Oroborus, the CCR 2000 shared a lot of design points with the MK 15. It had very nice PC software including a full simulator, log software, and decompression planning. It used VPM, but the algorithm was tuned to match Buhlmann profiles. People really didn't believe in deep stops back then.
It had two independant computers that communicated across an SDLC link. It incorporated a custom RTOS and was writted by a guy whose name is well known in the embedded computer world (but unknown in diving). I continued to dive my CCR until 2003. A few of them are still in use in commercial diving and Dan still has some parts.