Every now and then, students and researchers purchase textbooks from Vitalsource Bookshelf. Most of the books downloaded from VitalSource Bookshelf are in VBK format and protected by DRM. People want to be able to convert vbk to PDF or Epub and then read it freely.
VitalSource is very strict and responsive to drm protection, so removing drm to get content will be half the battle. However, they provide an online reader, and our method is to use this reader to download the content of the books and convert the VBK to PDF or Epub according to the format of the books themselves.
Developing a software to download VitalSource content is extremely difficult for the average user. z3kit VBK Downloader can help you. We have done market research and this is now the only software that can download VitalSource books.