From Forum Nokia Wiki

Open C is a major extension to the Symbian development environment. It is a set of standard POSIX and middleware C libraries for the S60 platform that increases developer productivity by enabling the reuse of existing software assets. Open C will be part of the S60 3rd Edition, FP2 release in 2007, and will be available as a plug-in that developers can use to create applications for earlier S60 3rd Edition devices.

Webinar Links

Getting Started with Open C

Open C Introduction for new S60 developers

Open C Introduction for Experienced S60 developers

Increasing Developer Productivity