@TEKNIK, I love what you are trying to bring to the table. A program that can spit out all the data for a particular light and be adjusted to a specific design is awesome. However there are some major obstacles that will prevent you from seeing your dream becoming fully realized. My first problem is that you are trying to make this a 'free' resource, instead this program and the IES files that run in it need to be your 'intellectual property' and you need to be a 'light engine consultant' that can show the pros and cons of different lights in a fancy program that sells the time and effort you put into the files (aka at your cost). Not very many average consumers are going to be chomping at the bit to download a program, grab the IES file to run in the program and then apply it to their small space (Not yet at least). You need to be contracted with large operations that need to know these types of things due to the fact that at their scale a wrong purchase is a business ending move, where as the consumer will only be slightly setback and will be able to recover.
I do believe that your dream of an open source where any lighting company that wants to be reputable and able to sell units will need to supply IES files and every consumer small and large will be able to use this information to their advantage. We are just not at the point where you can offer it for free to everyone.
So here is my advice to you
1. become a lighting consultant and land some contracts
2. run the tests for the client depending on which lights they are considering
3. spit it out in your fancy program
4. get paid and do it again
From what you have described this stuff sounds promising, your aspirations are just a little too liberal at the moment.