Audio/Video Capture

Mac Video Capture: Basic information about capture devices for OS X.

Mac Audio Capture: Information about audio capture, recording, and management on OS X.

Recording

ScreenFlow: Screen recording software that also offers post-production and encoding features.

Norichan: Designed to record from EasyCAPs (Syntek model only). Handles composite video very well.

EasyCapViewer: Alternative to Norichan. Its recording feature isn't as good as Norichan's, but it supports all EasyCAP models as well as vsync.

Syphon Recorder: You can use this to record anything that uses Syphon.

SyphonInject: Allows any OpenGL application to temporarily share its video frames with Syphon. It can then be selected as a source in Syphon Recorder or CocoaSplit.

Streaming

CocoaSplit: Stream software with support for Syphon, AVFoundation, multiple sources, CoreImage effects, preview editing, local recording, etc. The go-to stream solution for OS X.

CamTwist: Video broadcasting software that lets you combine multiple sources and produce professional-looking feeds. Can be used in conjunction with CocoaSplit.

Open Broadcaster Software: Currently unfinished, yet functional alternative to CocoaSplit.

Kumari: Simple desktop region streaming. It does not support overlays, window capture, or CBR, but is very lightweight and simpler than any other option.

Wirecast: Very expensive alternative to CocoaSplit.

QuickTime Broadcaster: Another alternative to CocoaSplit. Very out-of-date, but still usable.

Flash Media Live Encoder: Very antiquated option. Does not support x264, Syphon, or CamTwist 3.0, but can still be used with old versions of CamTwist.

Encoding

Yua: Encoding software designed to easily and quickly produce SDA-accepted videos.

ffmpeg: Command line swiss army knife. It does decoding, encoding, streaming, conversions, everything. More flexible than anything else but has a learning curve.

HandBrake: Powerful encoding software. Less simple than Yua as it requires standard encoding knowledge to use properly.

Avidemux: Same as HandBrake.

Compressor: Same as HandBrake. Part of Apple's suite of pro applications.

Timing

Time Split Tracker: Simple split timer with support for images and customizability.

Llanfair: Same as above. Requires Java.

ShitSplit: Handles in-game time for games like Sonic.

Splits: Same as TST.