I purchased this a while back through Ignatius publishing, although I only just recently installed it. (They were supposed to send me a Mac version, since that’s what I use at work, but only sent me a Windows XP version which I had bought for use at home. I have Microsoft Virtual PC and WinXP installed on my Mac, so I eventually put it on here, but naturally it runs quite slowly so I still don’t use it much.)
The company’s website is faithdatabase.com/ ; and as a comprehensive collection of early Christian writing, plus a very strong selection of Western Catholic material, it would be tough to beat for the price. There are over 1500 works, some of which are as large as the Bible itself (in several translations, of course), and the creators are constantly updating and including new material. A one-time purchase gets all this installed on the computer (with free online updating–in fact, internet access is required for the install process, which shouldn’t be a problem for anyone reading this recommendation.)
Added bonuses, of special interest to Catholics, are the full bodies of work of the most popular (free access) apologists, including (a major draw for me) G. K. Chesterton. But the collection also features the full works of Luthor and Calvin, and even a translation of the Qu’ran. Any of these can be printed out in various formats for ease of reference away from the computer. Plus there are several full encyclopedias.
I knew I had scored a major reference purchase when I discovered that a very impressive (if not entirely full) set of ancient heterodox texts (spurious epistles, acts, Gospels and similar tracts) had also been included. While the collection is clearly geared to serve Roman Catholics (of which I am not one, though I respect them), it makes a good bid to be a written history of chief opponents to Catholicism as well. (Specifically Eastern Orthodox authors, unfortunately, are notably absent at this time, as are most works still under original copyright for obvious reasons.)
Universalists or non-universalists, trinitarians or non-trinitarians, Christian or non-Christian, anyone interested in the history of Christianity and looking for a relatively inexpensive resource base, could do a LOT worse than picking up this handy software.