This website would not have been possible without the support of my wife Hélène and later the tolerance of my daughter Irène (who was born in the middle of this project and is now seven years old). Both put up with me staring into my laptop late into the evening while my telescope sat neglected in its box.
What I was staring at most of the time was information from the Astrophysics Data System (ADS), which now has links or content for 4.3 million documents and must therefore be one of the greatest public science libraries ever created. You can read more about the sources of the galaxy map data here.
You can read more about the early origins of this project here. This project really became possible in October 2000 with an email message from Professor Roberta Humphreys. When I was using the ADS to research distances to OB associations, I soon found that all roads (and at least 700 citations) led to Professor Humphreys's 1978 paper "Studies of luminous stars in nearby galaxies. I. Supergiants and O stars in the Milky Way".
I wrote Professor Humphreys and asked her for the database of star distances she used to create her famous paper. I didn't really expect that such a busy and important astronomer would respond to an email from a mere enthusiast, but in fact she responded immediately, with inspiring encouragement and all the data I had requested.
Just last month as I write this, another Roberta, Roberta Paladini, also responded quickly to an enquiry and sent me distance estimates for more than 500 HII regions.
I am grateful for the help I've received from these and a number of other astronomers and I hope that this website plays some small role in popularising their very important work.