CamTwist is a broadcast quality live video switcher that doesn't have the broadcasting budget.

Features:

• Works in High Definition: CamTwist is a capable of 720p output. If you have an input card that supports 1080i or 720p CamTwist can even scale up to 1080p output as well.
• Works with HDMI Capture Cards: Up to three Blackmagic Intensity Pro cards can be added in to a MacPro allowing you to switch between HDMI, Component HD, Composite or Y/C. Combine DV bridges to get even more inputs.
• 50+ built in effects included: To get you started there are over 50 included special effects ranging from title overlays to bullet holes and even fire! Each effect can be customized to meet your own needs.
• Create your own effects: While CamTwist already includes amazing effect out of the box, it is very easy to create your own custom elements. Using Apple's free Quartz Composer additional elements can be created with ease.
• Stream live to the web: Using your favorite streaming provider such as Ustream.tv, Justin.tv, BlogTV, LiveStream, NuMuBu.com and many others you can stream your CamTwist produced shows live on the Internet. Want higher quality? CamTwist fully supports Flash Media Live Encoder as well as Telestream's Wirecast allowing you to stream HD quality content live online. Don't want to download and install software? No problem. CamTwist can be seen by most modern browsers as an integrated webcam so you can select it as a source in the Adobe Flash Player.

Note: While the software is classified as free, it is actually donationware. Please consider making a donation to help support development.