Open platform
SOFTWARE SYSTEM WHICH IS BASED ON OPEN STANDARDS, SUCH AS PUBLISHED AND FULLY DOCUMENTED EXTERNAL APIS THAT ALLOW USING THE SOFTWARE TO FUNCTION IN OTHER WAYS THAN THE ORIGINAL PROGRAMMER INTENDED, WITHOUT REQUIRING MODIFICATION OF THE SOURCE CODE
Open Platform
In computing, an open platform describes a software system which is based on open standards, such as published and fully documented external application programming interfaces (API) that allow using the software to function in other ways than the original programmer intended, without requiring modification of the source code. Using these interfaces, a third party could integrate with the platform to add functionality.