S60 platform evolution

According to the Nokia platform compatibility promise, all devices based on a certain platform edition are compatible with the core software of that edition. On top of that, later platform versions may introduce new functionalities as lead features (Feature Packs), but they are not allowed to introduce breaks or incompatibilities to the core software of that edition. Typically most lead features introduced with the feature packs on top of the core software of the current edition will later become part of the core software of the next edition. Also individual devices may introduce lead features, but again are not allowed to introduce any breaks or incompatibilities to the core software of that edition. In practice, some small and very minor breaks may still occur, which are then documented and communicated.

Breaks and incompatibilities are only allowed when introducing a new core edition of the platform, but not preferred with those either. Going from 2nd Edition to 3rd Edition, which was not binary compatible with the earlier releases, there were more breaks on the source code level, and therefore migration from 2nd Edition to 3rd Edition was less trivial. Typically at least some level of rework was needed to make existing S60 applications run on devices based on S60 3rd Edition. However, compatibility will be maintained after that between the future releases, including S60 3rd Edition Feature Packs.

The following figure illustrates the evolution of the S60 platform.

Figure: S60 platform evolution with possible break points

The following figure illustrates the evolution from the S60 2nd Edition to the S60 3rd Edition. It also presents the version of underlying Symbian OS and lists main new features in each release.

Figure: S60 platform evolution from 3rd Edition Feature Pack 1 to 3rd Edition Feature Pack 2 with key feature additions and the version of Symbian OS, on which the platform is based