Nokia today introduced a new Feature Pack for S60 on Symbian OS. S60 3rd Edition Feature Pack 2 is designed for innovation and significantly facilitates the creation of compelling applications and accelerates performance.

Development of applications and services for S60 devices will be faster and more cost-efficient as S60 brings a major extension to the C++ development environment with Open C. This introduction brings the familiar standard C function libraries to S60 software, supporting increased productivity and improved time-to-market of applications. With Open C, developers can reuse existing code and focus on the mobility aspects of their applications.

Symbian recently introduced four of the basic POSIX libraries on Symbian OS. With Open C, S60 is extending the reach and implementing five additional C libraries for an optimized solution to migrate open source and desktop applications to S60 on Symbian OS.  Open C libraries are part of the S60 3rd Edition Feature Pack 2 and will be integrated into the publicly available software development kits. 

Feature Pack 2 comes with improvements in usability and software architecture focusing primarily on the mid-range device category. Usability enhancements support the ease of use in for example messaging, multitasking and downloading. Feature Pack 2 also enables instant media playback during downloading and animated notification of inbound calls. Architectural improvements focus on ensuring excellent performance and flexibility of S60 in various hardware configurations, and include for example support for demand paging virtual memory technique. 

S60 3rd Edition Feature Pack 2 will be available for all S60 device manufacturers in Q2. It is fully compatible with S60 3rd Edition, and applications developed for 3rd Edition will run on all Feature Pack 2 devices.

s60 blog has a nice feature introduction here