@chapter(Introduction)
@section(Development Goals)

Galatea was originally conceived to support the Electronic Light Table
project at the MIT Media Lab.  This project was an application which
permitted users to retrieve images from video disks into small on-screen
"slides."  The intended purpose of this application was to provide users
throughout the MIT campus with a simple method to access a large central
bank of image data.

In order to control the centralized bank of video disk players, a
client/server video control system was required.  There were two such
systems available for this purpose.  One was created by Professor James
Anderson of the MIT Architecture Department, the other by Russell
Sasnett of MIT Film/Video.  Although each of these systems provided
most of the functionality required, neither could be used on a large
enough scale to provide campus-wide distribution of video information.

During the summer of 1988, development began on a network video device
control system capable of being scaled for campus-wide use.  Campus-wide
use did not mean that the system would be deployed on many standalone
computer systems, but that there would be many systems interacting and
competing for access to distributed video resources.  The resources
devoted to serving the whole campus were a pair of Digital Equipment
Corporation VDP50's video disk players and a BOA Source Controller II by
Presentation Environments to switch the audio and video between the two
players.  These three units were controlled via RS232 by a DEC MicroVAX
II which was connected to the campus computer network.  The output of
the BOA video switcher was modulated and transmitted over the MIT cable
system.  Any location requiring access to the video disk players needed
access to both the MIT cable system and the campus computer network.
Additionally, it was common for a user's computer system to have its own
local video resources.  The "distributed" nature of the system stems
from the need to control video devices on multiple computers without
additional work by the user or the client applications.  The results of
these experiments with the centralized bank led to the development of
the first version of Galatea.

The style of the programming interface was designed to be similar to the
C language interface for the X Window System.  Since many applications
using video in this environment were going to be created using X,
creating a similar programming interface eased the programmers burden.
Galatea is also intended to be a companion to X, and works very well in
that environment, although only one sample Galatea application actually
requires the presence of the X Window System.  Galatea is available
under the same copyright restrictions as X.  A person may acquire all of
the source code from publicly available sources, but must maintain the
MIT copyright notice on all copies.