Design and development of on-line computer software systems to provide real estate research services and real property appraisal data in the form of: data-acquisition and collection for storage and delivery of real property parcel images comprised of still photographs and moving video; retrieval of public documents; hosting of photographic and videographic data and provision thereof to subscribers and licensees of an online service; combining photographic and videographic data with data derived from public documents and providing same to subscribers and licensees of an online service