France Business Visa For Attending OpenSource Conference

I have been invited to speak at EuroBSDCon 2017 in Paris this year. First of all, a bit about me and the conference.

I'm a software engineer based in Hyderabad, India. I am also a contributor to the NetBSD project, which is a volunteer driven open source project. There are thousands of developers all around the globe which contribute to NetBSD and other similar open source projects (such as FreeBSD and OpenBSD).

Every year, the contributors to these projects gather at conferences such as EuroBSDCon, AsiaBSDCon and BSDCan. EuroBSDCon is organized at different places in Europe every year. Last year it was organized at Belgrade, Serbia and this year it is being organized in Paris, France.

I have two questions regarding the visa process:

I am not sure if I should be applying for a tourist visa or business visa. The first reason being that I am not attending this conference on behalf of my employer. Second, I will not be doing any official business there. So, a business visa doesn't make sense to me. But, on the other hand almost every travel agent suggests going for business visa for attending conferences.

Although, I could ask my employer to support me for getting a business visa. But the conference is organized by "The EuroBSDCon Foundation", which is a non-profit registered in the Netherlands. The business visa requirement for France says to "submit an invitation letter from an organization established in France". Which is not possible in this case.

I am hoping people who have faced similar circumstances and travelled would be able to suggest me the correct way to go for the visa.

EDIT: This is not similar to the case of an academic conference. Academic conferences are organized by Universities and attended by students, professors, researchers. While in my case, it is a volunteer driven conference attended by volunteer developers from around the world. Consider it like the various Wikipedia editors organizing a conference to talk about their work to improve Wikipedia (just an example).