I am so amazed by the books you have written for 5th Edition that I have read, you guys are really a fresh breath of Air in this business (even though you have been going on for so long).
The writers for Ars Magica are mostly freelancers. I'm a freelancer, so I can't answer the questions about Atlas's internal structure.
As to education, I have honours in history, a graduate diploma in information studies (which is my professional librarianship degree) and a masters degree in business. I work as a public librarian (and now I've mentioned that I need to note I don't represent my employer on this forum.) I also have technical certificates in various things, am a Coursera addict, and am about to enrol in an adult teaching certificate. I'd note I didn't have any of these things while writing Sanctuary of Ice, so people shouldn't let a lack of history qualifications put them off. Being willing to put in the hours is more important that having a qualification, IMO, particularly since there's a sort of ethos of helping each other out among the authors.
Thanks for the compliments.
It depends on what you mean by "work with." All of us have some work related to it, whether checking proofs from the printer or packing boxes of ArM books in distributor orders. The line editor for Ars Magica, David Chart, is technically not an employee but a freelance independent contractor; the writers and artists are all freelance too.
Some freelancers have only recently started to work for the line, some have been involved since the game was owned by White Wolf or even before. (Artist Jeff Menges, for example, has illustrated books all the way back to 2nd Edition in the Lion Rampant days.) I've been with Atlas since I started it in 1990, of course, and before that I was involved with ArM's original publisher, Lion Rampant, starting when the 2nd edition was in development.
Many books have "about the authors" sections with short biographies.
I've been working on Ars Magica for twenty years. My first published work was a character and setting for Ars Magica 2nd Edition, although it came out (in White Wolf Magazine) shortly after 3rd Edition was released. I have a Ph.D. in philosophy. The freelance authors do their own research in and around their day jobs; only one of the authors is actually a professor of medieval history. (Although, from the other direction, yes, one of the authors is actually a professor of medieval history: Niall Christie. He hasn't had time to write much for us recently.) Reading the author bios across several books will tell you quite a lot about the authors, although there's a tradition of working in joking references to the book in question that makes them less direct than they might be.
The playtesters don't get paid by us, but they also do their own research.
I don't work full time on Ars Magica. I also teach, and develop and design examinations in logic for the Japanese market. In fact, I don't think anyone works full time on Ars Magica; the people who are full time at Atlas also have other things to work on.
This is true. People help out with the things they've researched. Mark Shirley knows a lot about medieval metaphysics after Art and Academe, Timothy is a librarian and so knows how to find out about, well, anything, CJ knows a lot of folklore, Niall is a professor of medieval Islamic history, and so on. Anyone with the enthusiasm could write for game, although you do need the enthusiasm, and the ability to cope with being told that the basis of your draft is unmedieval and needs to be redone. (Access to a university library is an advantage, too.)
I really don't know why people keep writing for us, but I'm very glad they do.
It was vital back in ArM4 days, but I don't have access above "member of the public" to one now, and there are ways of getting by. 8) The digital revolution in libraries has meant a lot of our sources are free and legal online, or free for library members online. For example "The Magnificent Century" by Costains is on OverDrive, and that was source material for a lot of Lords of Men, and some of Tales of Power, and some of Tales of Mythic Europe.
I think this is one of the reasons we have authors so strung out around the world. It's because the old geographical advantages, although they still exist, are less pronounced than they were.
Perhaps too librariany, there.
Oh, I do not have all the books yet and I refuse to download them from various torrents as I prefer to support the games by buying the games that I play.
That is why I asked.
But as I said, all you writers - you have truly impressed me and I can't see myself ever leaving this wonderful game. The writers has made a really living world of magic and true history and I am really happy that I found this game. Thank you all for all your work this far and for all the hours in the future that you will put into making my life filled with mysteries and magic 
Just to be clear - purchasing the pdf files from e23 is perfectly legal and supports Atlas. I have no idea how much of the digital price Atlas receives, or how much of the regular retail price it receives, so I can't judge which supports Atlas more. I do know that whether you purchase a digital or hard-copy you are supporting Atlas, and that it encourages both.
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Oh, that I know, but I want hard paper books. I do not like pdfs, legal or not.
PDFs are awesome!
Searching is great. If you have an eidetic memory, great. If not, searching is really handy. And then when I go places to play, I can have my iPad with the PDFs right there with me... I have copies of several of the books, but as soon as the Ars Magica 5th Edition core book became available in PDF, I grabbed it, and never looked back. 
This! +1 
Well, speaking for myself, I would say it boils down to the social rule of reciprocity: when someone gives you something, you owe them to give them something back. The Ars Magica community gave me the best RPG ever, and after a while it became clear I could give back some of my ideas.
I agree with Andrew, it's something to do with giving something back to this great game and setting which has fascinated one for so long, and continues to do so.To be part of this, to write for this, is great. In all the down-time between game sessions I enjoy still thinking about Ars Magica. About characters, plotlines, covenants, sagas. So writing something is a useful way to spend time if you're already in that mindset.
Sure it is challenging due to the huge amount of already published material and rules you can't contradict, the medieval history, paradigm and myths you need to respect, the difficulties in writing something as flexible and appealing to a majority of readers and players - and for me also writing in a non-native language. Even daunting at times. But the support and help from the Line Editor and the other authors is invaluable.
Oh, and regarding education I have a BSc Eng, not very useful for my writing, but good enough for a day job.
I do it for the money, I need to keep up payments on my yacht! :mrgreen:
Seriously though, the line Editor David Chart does a heroic job, organising, recruiting, guiding, editing and working closely with each and every one of us. Sometimes that can be hard work, as we all have our own visions of where things should head. Trying to get it all to work is a herculean task, and he does a magnificent job. Without his efforts, and those of the playtesters, the artists and all the folk at Atlas Games the line would probably be abysmal, if any books were ever produced, at least based on my first drafts
I missed the education question: I spent some years at college, but I'm not sure that is necessary to write for the line. In fact I am absolutely sure that it isn't, or necessarily helpful! I have a few postgrad degrees in largely irrelevant things, though a BA (Hons) in History & Religion was my first degree. My academic work has been in cultural studies, history, theology, philosophy, art history, psychology, and my main field these days is parapsychology.
I put about 35 hours a week in to Ars Magica at the moment, though that is because I'm a running a concerted recruitment campaign, Arcane Connection the Ars Magica podcast, three Ars Magica weekly sagas and may or may not be doing some writing too. Oh and this week I'm writing two Ars scenarios, an Ars Magica epic boardgame and a Ars freeform as well as organising for Grand Tribunal UK, the Ars Magica convention (www.grandtribunal.org). Given I have other commitments this will be reduced after September I suspect, when I'm supposed to be lecturing on a part time basis as well, though not in Ars! Obviously none of the above (bar the writing) is paid work - I do it because it's my passion I guess.
(And I don't have a yacht - I can't afford to repair my pushbike even!)
cj x
I'm a minor contributor to the line (4 chapters, 5 if you count the Book of Mundane Beasts). So I'm not very important in the grand scheme of things, but to answer your question: I have a bachelor's degree in physics, a Master's in mathematics, and more night school and professional development course work in software engineering than I care to admit. In my day job, I'm a software engineer and researcher.
I also happen to have been reading medieval history for fun since I first discovered Ars Magica in 1989, so that kind of compensates for the dearth of humanities in my formal education. 
I just remember getting turned on to history when I was looking for a site for my first Saga, picked Aquitaine, and discovered that Aquitaine was ruled by the English crown in 1197 (the official starting date for 2nd Edition). That blew my mind, and I have been puttering at trying to unravel the complexities of medieval society ever since.
I'm even smaller fry than Andrew, having only had two of my projects published to date - although I did a lot of work on the first (3 chapters for The Cradle and the Crescent), I only contributed to part of Marko's "City of Brass" chapter in Tales of Power. My other chapters haven't reached print yet and I now have less time than I once did.
I'm a full-time medical practitioner, which is virtually useless for writing for Ars. I do particularly like the Medicine section of Art & Academe, not because it is accurate in modern terms but because it is actually wonderfully authentic thanks to Mark's efforts. It also reminds me to be humble that many greater minds before me were convinced they knew the truth but were so incredibly mistaken.
I really don't need to do this for the money. I do not own a yacht, nor do I ever plan to. I enjoy writing and I think Ars is a great game so I'd like to give back by exerting my creativity in a way that gives others enjoyment. I have learnt a great deal about life, time management, responsibility and communication through writing for Ars and working with David as editor for which I am grateful.
I don't have a PhD or a history degree (I never even studied history in school to be honest although I did learn some Latin in high-school). I do however read a lot and always have, predominantly folklore, mythology and more esoteric non-European history. I fortunately have access to a fantastic local library, limited but still useful access to a university library and an unfailing tendency to spend money on books instead of food which has resulted in a book case overflowing with texts on a wide array of medieval topics. Since writing the Jinn section and doing a vast amount of reading on Middle Eastern folklore, I've amusingly become "the Jinn guy" which is far less useful than Mark knowing all about medieval metaphysics or Timothy being the doyen for anything Faerie but it comes in handy.
In terms of research, a good relationship with the other line authors certainly helps. I've asked Timothy to use his librarian kung-fu on a couple of occasions for me and I'm always impressed by the results. Niall is always generous every time I badger him for Arabic terms, which given I like writing about almost anything other than vanilla Mythic Europe, is an invaluable help. For my part, I can sometimes help point other authors in the right direction if I've read something on the topic or have it in my collection (which is almost the same thing, but not quite as I can't read everything I buy).
I have every ArM5 PDF (bought legally from e23). This allows me to search every relevant book I may need to check when I write and carry the majority of my Ars library on my iPad using DropBox. I tend to write large sections while on leave or in between sessions at conferences (sometimes during boring sessions) so this helps a lot.
For those who are curious (and since none of this is secret or anything): We get 80% of the money for sales through e23; we get 75% of the money from Paizo sales.
Depending on where you're buying it, we are typically getting between 40% and 60% of the cover price on print books.
It never occurred to me I could get a PDF copy of the core rulebook (I assumed that would always be in print so never published as a PDF). However, finding out that I can get one, I did! That will reduce my burden at times in the future so thanks.