Golgotha Graphics eBooks are are published in fixed-layout EPUB format, and sold though two platforms – both of which offer free previews, which should allow you to test whether the eBooks work on your device, and within your choice of reading application:
Apple Books: eBooks purchased use Apple’s Fairplay DRM, and can only be read in iBooks / Apple Books. An iTunes account, and an Apple device (Mac, iPhone, iPad etc) are required to make the actual purchase in the iBooks / Apple Books app.
Books can receive updates at no additional cost (aside from your bandwidth costs), should errata updates be necessary.
Fastspring: eBooks purchased are DRM-Free, may be purchased on any device with a web browser, and read in any application capable of reading Fixed-Layout EPUB – iBooks / Apple Books on Apple devices, or Thorium on Apple devices, Windows, Linux etc.
Books are sold “as is”, however we are currently working on a cross-platform application to allow post-purchase patching of an existing EPUB, with a .zip file containing only the modified files from within the EPUB, should an errata fix be necessary.
Should this application not pan out, since the files are DRM-Free, applying an errata fix is a simple matter of unzipping the .epub file, and then manually copying the updated versions of images, text files etc. to the appropriate directories, then re-zipping the .epub.
Regardless of the platform, or DRM status, the conditions of sale are that you will respect the copyright notices contained within, and not duplicate, share, or in any way, increase the total number of extant simultaneous possessors of the works. If you obtain an instance of any of Matt Godden’s books, that individual instance must have been purchased via Golgotha Graphics’ official channels.