S60 2nd Edition, Feature Pack 3 is based on Symbian OS v8.1a. For additional information about new features in this release, refer to the document S60 2nd Edition Feature Pack 3: What's New - Lead Features and APIs.
For additional information about the Symbian OS v8.1 operating system, visit the Symbian OS Technology Web site.
See also What's New For C++ Developers In Symbian OS v8.1?. These differences between platform releases result in some software forward and backward compatibility issues that developers must take into account when building applications designed to run on devices that use different platform versions.
S60 2nd Edition, Feature Pack 2 is based on Symbian OS v8.0a. For additional information about new features in this release, refer to the document S60 2nd Edition Feature Pack 2: What's New - Lead Features and APIs.
For additional information about the Symbian OS v8.0 operating system, visit the Symbian OS Technology Web site.
S60 2nd Edition, Feature Pack 1, based on Symbian OS v7.0s, provides extended functionality and a number of new APIs for the S60 platform. For additional information about this release, refer to the document S60 2nd Edition Feature Pack 1: What's New - Lead Features and APIs.
S60 2nd Edition is based on Symbian OS v7.0s, whereas S60 1st Edition is based on Symbian OS v6.1.
Detailed information about the new features for 2nd Edition is available in the document S60 1st/2nd Edition: Differences in Features.
For additional information about Symbian OS v7.0s, visit the Symbian OS Technology Web site.