iMovie is a proprietary video editing software application sold by Apple Inc. for the Mac, iPhone, iPad, and iPod touch. It was originally released in 1999 as a Mac OS 8 application bundled with the first FireWire-enabled consumer Mac model – the iMac DV. Since version 3, iMovie has been a Mac OS X-only application included with the iLife suite of Macintosh applications.

iMovie imports video footage to the Mac using either the FireWire interface on most MiniDV format digital video cameras or the computer's USB port. It can also import video and photo files from a hard drive. From there, the user can edit the photos and video clips and add titles, music, and effects, including basic color correction and video enhancement tools and transitions such as fades and slides.

iMovie HD included support for HDV (720p and 1080i) and integration with the rest of the iLife suite, with toolbox buttons allowing the importing of images from iPhoto, music from iTunes and the setting of chapter markers ready for exporting to iDVD.

Chroma key compositing, or chroma keying, is a special effects / post-production technique for compositing (layering) two images or video streams together, used heavily in many fields to remove a background from the subject of a photo or video - particularly the newscasting, motion picture and videogame industries. A color range in the top layer is made transparent, revealing another image behind. The chroma keying technique is commonly used in video production and post-production. This technique is also referred to as color keying, colour-separation overlay (CSO; primarily by the BBC), or by various terms for specific color-related variants such as green screen, and blue screen - chroma keying can be done with backgrounds of any color that are uniform and distinct, but green and blue backgrounds are more commonly used because they differ most distinctly in hue from most human skin colors and no part of the subject being filmed or photographed may duplicate a color used in the background. It is commonly used for weather forecast broadcasts, wherein the news presenter appears to be standing in front of a large map during live television newscasts, though in actuality it is a large blue or green background. When using a blue screen, different weather maps are added on the parts of the image where the color is blue. If the news presenter wears blue clothes, his clothes will also be replaced with the background video. A complementary system is used for green screens. Chroma keying is also used in the entertainment industry for special effects in movies and videogames. The advanced state of the technology and much commercially available computer software, such as Pinnacle Studio, Adobe Premiere, and dozens of other computer programs, makes it possible and relatively easy for the average home computer user to create videos using the "chromakey" function and easily affordable greenscreen or bluescreen kits.