This list is always changing. You have two options when it comes to watching video: either download it first, or stream it in "real time" and watch it play as it is sent to your computer.

1- Streaming. Generally, "streaming" video refers to movies that play as they are sent over the Internet, in real time.

    Real 7 & Real G2
    QuickTime 4 (RTSP)
    Windows Media (ASF, formerly, NetShow)

Someday, all web video will stream, like television - but on demand.

The Good:

Instant gratification.

Longer movies.

Multiple movies for multiple bandwidths.

They don't save directly to your hard drive - which is great if you're a filmmaker worried about someone stealing original material.

The Awkward:

More erratic frame rate and image quality.

Information may be lost as it's sent over and so quality might fluctuate unpredictably (which can be good in a postmodern sort of way, depending on how you feel about it ... one day it will be called "retro").

Potential for out of sync audio and video.

Can only be transmitted via a special "streaming server".

Recommended Uses:

For longer movies.

For broadband.

For a live Internet feed of the Canadian Parliamentary elections or a Britney Spears concert.

For presenting footage where the audio content is of more immediate importance than the video, particularly over low bandwidths.

Comparison:

Both QuickTime 4 and Real 7 are cross-platform formats, compatible on both Macintosh and Windows operating systems. There is a Mac beta version of the Windows player.

None of these video formats are fully supported in UNIX. Flash does have a plug-in for UNIX.

Windows Media Player only works well in Windows 95+ and it sometimes tries to play your QuickTime and RealMedia files. Problem is, since it isn't equipped to handle the latest QuickTime 4 and Real 7 files the viewer will say the movie is broken even when it's not.

RealMedia offers something called "SureStream" which gauge a viewer's connection speed and switch between high-, mid- and low-datarate versions on the fly.

QuickTime offers "Multiple Data Rate" movies which are predetermined to play for certain connection speeds. They don't change on the fly.

Real files cannot be edited or recompressed once encoded in the Real format.

Windows Media Player has absorbed older streaming formats such as VDO, VExtreme, and Vivo.

2- Non-Streaming. Movies download (either partially or entirely) before they are played. This takes away from the immediacy of the movie watching experience. On the up-side, the final image quality and frame rate are predetermined.

    QuickTime
    MPEG
    Microsoft DirectShow (formerly, AVI)

The Good:

Offers more control over image quality and frame rate.

Potentially offers superior image quality (because it is predetermined).

Can be downloaded from any server.

Can be saved to a hard disk.

The Awkward:

Downloading...

Files can be very large and require more waiting than the movie is worth.

Rarely utilized to full potential.

Recommended Uses:

For shorts - a few seconds to a few minutes.

For video bites.

For a movies where absolute quality means everything.

As an alternative to GIF animation (although Flash is also excellent for this).

Comparison:

QuickTime is really the only format that is as robust an authoring tool as a playback tool. That's why there's so much attention placed on it in FlickTips.

MPEG is listed here because it's been around. MPEG-1 is the thing for UNIX because most other QuickTime and Windows formats don't go there... yet. (MPEG-2 is the standard for DVDs, you've probably heard of MP3, and MPEG-4 will become more common along with broadband technology.)

And Microsoft has, yet again, proved that it's the kid with all the toys.