There's a bit of a history here, actually, that will at the very least provide some backstory.
Originally I was the only active developer (I took over from PY. There was very little overlap between the two of us working on the program at the same time). After a handful of versions, I spent the summer after my sophomore year at University to implement some brand new things. New physics based on springs that was a vast improvement over the old system, which involved lots of bail wire and duct tape. (This is largely the physics the current version uses, I believe. Eric has done some tuning and such, but the core is probably pretty much what I built that summer). I also revamped the DNA to be less structured. It used to be that genes were rigidly defined as a cond-start-stop triplet. I spent some effort to allow for more complex or even nonsensical DNA. There were lots of other changes, too, but those were the big two. This new version was packaged as 2.4
2.4 had some problems. Lots of problems, and lots of bugs. It was really almost entirely unusable. 2.4 was really a failure on my part, having underestimated the amount of time it takes to go from a "feature complete" milestone to something that's stable and ready for end users (and lacking a lot of experience coding for an audience at all). School had started back up and I was extremely busy and frustrated with the VB code. Not just fixing bugs that I really should have caught in the first place, really the whole way the language worked. It made trying to implement various "advanced" features exceptionally hard (there was an abortive attempt at a bucket system to sort bots by buckets (eg: sectors) for faster collision and vision code that was made much harder by the limitations of the language and my ability to adapt to them).
So I stopped working on the VB version, and most people continued to use the older 2.37 version. Instead, I started porting sections of the code to C++. This wasn't a rewrite, it was very close to a straight port. I fixed a few bugs in the process as I worked through the code, but the C++ version would have looked very familiar to someone working on the VB source. You can probably find the C++ version in some repository somewhere linked on the wiki. It got pretty far, but I ran in to a brick wall with the physics. I wasn't using any external libraries or anything, it was a rigid body simulator (rigid bodies being limited to circles exclusively) I'd implemented entirely on my own. What I wanted to do with multibots just didn't work with the new version (or old version for that matter). Plus there were some threading issues. Also, the code, being almost a direct port of the VB code, was still a pain to work with. Something like the robot class was thousands of lines of convoluted code, with lots of interdependencies between disparate classes (the shots class was a friend to the robot class, and vice versa). So I gave up on the C++ version and spent some time working through how to actually achieve the sort of physics I wanted. This was the end of my junior year at University.
Sometime during this process, Eric joined the community and decided he wanted to try and fix issues with the 2.4 source, since it did have some nice features even if it was a bit buggy. After a few months of effort he was able to get even the hardliners to move from the 2.37 version to the new 2.4X version. And he's been supporting that version ever since(roughly two years), adding features and fixing bugs as people suggest them/find them.
I, in the mean time, decided to start over with a complete rewrite from scratch. Because of its similarity (in a good way) with VB, I chose to try again in C#. To get the ball rolling I wrote about 75% of a DNA module in C# (actually wrote it twice. The first time to get a taste of the language). This was right when I first learned about unit testing (maybe a year and a half ago), so the vast majority of the DNA code is unit tested and, I think, pretty stable and bug free.
Then I spent about 8 months working on an entirely different project (A
3D version of something like SimEarth). Obviously not a lot happened with Darwinbots during that 8 months. Eventually Darwinbots coding started to interest me and I put my other project aside. After some abortive attempts at using existing libraries (most didn't last more than a few weeks) I thought I'd try my hand at building my own physics engine again. Unfortunately, most of what I wanted to do had never been attempted before, so there was a lot of original research on my part. That started about a year ago maybe and continued until maybe 3 months ago. During the 4th of July weekend I scrapped the physics work I was doing and concentrated on getting re-acquainted with my code, reorganizing the file structure and fixing various annoyances with Visual Studio project files and temp directories and such. Lots of meta programming kind of stuff. I got my present job as a junior programmer for a video game company last March. When you program 50-60 hours a week for a job it's hard sometimes to drum up the mental effort to work on part time coding projects, so progress has been... glaciatic. I've put maybe 100 hours of work in during the last 3 months (though I finished a major milestone last week, so I can relax and go back to 40-50 hour weeks for a while. Plus I have a 3 day weekend coming up which I'll probably spend, at least in part, working on Darwinbots).
During the time I was either not working on Darwinbots or working on physics, Eric's been supporting the 2.4 code. He takes a few months off during the summer, but otherwise puts a lot of time and effort in to supporting the current version for users. He tends to work slow and steady, where I've always been of the burn-out super nova explosion of coding school, where I spend about two weeks doing a massive sprint of thousands of lines of code then do nothing for several months So Eric's understandably a little skeptical of any claims I make.
Heh, that's a little long winded, but that's how things ended up where they are.