When I inherited the system, the basic architecture was fairly satisfactory, despite not being built on a recognised framework or technology.  It had clearly been re-worked by several previous developers and styles, revealing some fragmentation.

• For example, two different database abstraction layers were in use, which was redundant. 
• And the database account username and password was specified identically in seven different files, making it an irritation to move the software to any other host. 
• There were many missed opportunities for CSS styles, so that some pages showed in Times font, others in Arial or Verdana.
• Identical code fragments were moved into one re-useable function, for example, to achieve a common presentation of page header

I addressed these and many other lower-level issues to improve the general engineering aspects. As for functionality, the biggest failing was in the administration:

• I added or improved reports,
• I allowed the browsing and editing of course content, both using a JQuery TreeView, and by a chain of dropdowns connected by JQuery 
• Enabled searching for trainees or managers and improved editing of these records
• Created CSV and XML import and export of records
• User-friendly improvements to the video player (resizeable and buttons to move to other content)
• Created utilities to help administrators prepare subdomains for new clients, a backup system and symlinks for sharing content
• Prepared a Wiki for help text
• and many other features