Great news! You probably know of Logos Bible Software. They have been around for a long time, and have produced many valuable resources--all of which are well formatted and fully searchable. I have used their Bible Software for some years now. The folks at Logos have heard our pleas and have packaged a number of their best resources together into a "Reformed Library." For more information, a complete list of what is available, and pricing for the various packages, go here: Reformed Resources
The list of resources they are making available in their packages is pretty amazing.
1. Philip Schaff’s Early Church Fathers (37 vols.)
3. The Works of John Owen (24 vols.) (Includes Owen’s 8 vol. commentary on Hebrews)
7. The only English translation of Geerhardus Vos’ Reformed Dogmatics (5 vols.) (only available in Logos)
9. Bavinck’s Reformed Dogmatics (4 vols.)
10. Richard Muller's Post-Reformation Reformed Dogmatics (4 vols.)
This is only the stuff which I know will be of great interest to folks who frequent here. There is much, much more included in their various packages.
If you have questions about the Logos system in general, you can check out some of the new features Logos brings to theological studies with the videos found here: Features
For a video and some short descriptions of the datasets powering Logos 5, go here: Datasets
And last, this video answers some FAQ’s about how the resources mature and are enhanced over time with free updates.
This should be a great addtion to anyone's digital library!