This project has a weird history (like any other project, though).
I have an application and its dedicated website where I'm collecting some sort of data/statistics of the application usage. The statistics are automatically send to me by e-mail in a tabular report layout.
So, two weeks ago I said: "OK, but it should be nice if I would see some kind of trends, so I would grasp in a second what's going on without chewing 1000 data rows from the tabular report". That was the moment when I understood that I need some sort of PHP charts. I've googled the Internet, I've found some candidates, they've looked nice and mature projects. But they were more complex than I really need. So, naive like always, I said : "it will take me less time to write 100 lines of code then getting a lightweight bar chart than deploying a mammoth library and trying to figure how it works".
So I've wrote the vertical|horizontal bar chart in like one-two days, then I've thought it will require only few hours to extend the code so that it supports points/lines. Then I've said it should be a breeze to draw few arcs and to get a pie. Later I've seen a pattern so I've rewritten some parts of the code, moving the common parts to a base class. After one week, after playing with these charts and some real-life data I've understood that they really need to support multiple data sets so I've began to rewrite some parts of the code.
One week later it get a final shape so now I am using it in real live. I've thought that it would be nice if someone else could join to the project team and improve the work already done or at least if some other people might try using it.
So here we are, a GitHub like revision system, 1000+ lines of code in a library opened to everyone, this wiki and me, inviting everyone to take advantage and use a free lightweight chart library.