killerstormOK, a bit of history: There were several implementation attempts by different people, but (as far as I know) the only one which has decentralized market as a goal is called BitcoinX. It is like the mainstream of colored coins.
People who started it wanted to create an organization of some sort, but it didn't work very well, and basically I was the only permanent team member.
So I worked on it on and off for about a year. (Since September of 2012, when I made the first prototype.)
Until July of 2013 I treated it like a gig, but then I noticed that BitcoinX isn't going anywhere (lead developer of WebcoinX which was supposed to take over development sort of disappeared), but there is a demand for this technology, but nobody is doing it right.
So since July it is, like, my main occupation.
Still, progress have been slower than I expected: I wasn't able to recruit more people, and I had to split my attention between two projects: WebcoinX and NGCCC.
(In retrospect, I should have focused on NGCCC. My hope was that we can quickly make a WebcoinX demo which will help to popularize colored coins, but it looks like colored coins need a robust implementation more than they need popularization. On the other hand, I previously had some bad experience with ArmoryX.)
So the currently status: we are working on it, it is slower than expected, but there is hope that something will be available this month.
Also, as I mentioned elsewhere, sponsors are willing to provide 200 BTC to fund development, so that's not a problem.
More details about status:
I've recently written an article about the
theory of colored coins, it summarizes how it works on the low level, but with a dry language. I also plan to write an article about practical aspects of it, like color definitions/asset definitions, trade, issuance and so on. Meanwhile, all this information is available in
bitcoinX group archives, but you have to dig to find it.
NGCCC: We have coloredcoinlib and CCoinDemo prototype, but this prototype isn't adequate, and I'm currently designing a new core.
You can see preview here. Working version will be available in a couple of days.
WebcoinX: The plan was to implement a demo first, and to improve it to make it work on mainnet second. Demo is almost complete, but there was no development in last couple of weeks. [url-https://trello.com/b/n4qoNDDI/webcoinx]Here's TODO list[/url]