Hi,
I am the writer of OrganBuilder. I'm glad to see this project had some attention on MPS!
The project is not dead. During summer, I have been learning how to write portable code using Lazarus. I think I'm ready now, I wrote this other music software as training: https://sourceforge.net/projects/theremine/ (not related to organ, it implements a virtual Theremin)
I intend to make a new version of OrganBuilder in the future. But at the moment, work is taking all my time and I wont make significant progress before a while (probably months). I have a lot of ideas for next iteration. I will probably implement a full-featured editor that will allow defining custom appearances of the resulting organs. The main difficulty is probably to keep everything simple. If it takes nearly as much effort as writing the ODF directly by hand, that would be bad design.
Vincent