Apple has unveiled the fourth incarnation of its Final Cut Pro digital video and film editing software. The new version incorporates more than 300 new features and introduces a real-time compositing and effects system called RT Extreme that can be upgraded depending on processor speed. The technology enables Final Cut Pro users to view software effects in real time or via an external broadcast monitor when connected via FireWire or an external breakout box. Final Cut Pro version 4 is expected to be available in June for around $999 (£644). Registered users will be able to upgrade for less than half of that.