The integration calls upon the concern on what is the nature and origin of digital contents in both VLEs and digital libraries.

Akeroyd (2005) grouped the types of content found in e-learning as:
• Structured (published, quality material, standardised, bibliographic controlled, and peer reviewed).
• Less structured (course notes, handouts and the like which may vary from a lecture to lecture, is poorly structured and not subject to any bibliographic controls).
• Totally unstructured (which might emerge from discussion forums or e-mail lists and which is constantly changing and being amended).

For the integration to be achieved, all types of content should be considered together with the challenges that the diversified format and nature of learning content brings to information management and teaching and learning processes.

Digital portfolios (Roes, 2001) represent another challenge when dealing with content treatment.