The COVISA module suite is a set of modules that extends IRIS Explorer for collaborative working. The modules function in just the same way as all other IRIS Explorer modules, being launched from the librarian and connected into maps. This system gives the advantages of collaborative visualization without re-learning the visualization. Described below are the components of the COVISA collaborative system. A description of additional example collaborative modules is also available.

COVISA Server
This part of the COVISA collaborative system is responsible for: coordinating the joining and leaving of participants;  the connection and launching of collaboratively aware modules;  routing data between group members.  It is implemented as a process outside the IRIS Explorer environment. It should be run on a machine that is accessible to all potential participants of the collaborative session. Only one COVISA Server should be run for each collaborative session. The COVISA Server can be run in two different modes: The default mode of operation is referred to as 'Store and Forward'. In this mode, a copy of the last data object for each group is kept as it is passed through the server. When a collaborator joins late or makes a module reconnect (after being disconnected), they are automatically given a copy of the current shared object for each group. This mode can be started up by typing the command COVISAServer in a shell window. The second mode of operation is referred to as 'Pass'. In this mode data is simply distributed to collaborators as it is received, no copy being held at the server. This mode is more efficient if large amounts of data is being held, and suits certain styles of conferencing. When a collaborator joins late, one of the current collaborators must cause their sharing modules to fire so that the latecomer receives the current data set. This mode is accessed by typing the command COVISAServer -nsaf in a shell window. Help is available by typing COVISAServer -help in a shell window. The COVISA Server uses the COVISA_CENTRAL_PORT environment variable to set the port number it will use.
MServer - before connection.
	This is the MServer module which is used to make a connection to the COVISA Server, and hence join the collaborative session. The widgets that can be seen are as follows: The name of the machine where the COVISA Server is running. This can be pre-set using the COVISA_CENTRAL_MACHINE environment variable. The port number used by the COVISA Server. This can be pre-set using the COVISA_CENTRAL_PORT environment variable. When a collaborator joins a session, their name appears in the conference list text slot (see next picture). This name comes from the UserName widget, which is pre-set using the USER environment variable. Note: in order to see the menu bar you need to view the large image. This menu is used to toggle the MServer module's connection mode between: On-the-fly mode, where collaborative maps are dynamically created by the collaborators; or in Application mode mode, where previously constructed maps are used with IRIS Explorer in application mode. Once information has been entered in 1, 2 and 3 above, the start button is used to make the module attempt to connect. If connection is successful, then the module control panel changes to look like the next picture.
MServer - after connection.
	After connection to the session, the MServer module changes appearance to show the following information: The Conference List widget appears with the list of names of all current collaborators. Currently there is just one person in the session. As people join, their names are added, and removed when they leave. The Group Join/Find List widget appears with the list of all currently shared modules. It is currently empty indicating no modules are being shared. When a collaborative module is launched and initiated with the session (see below) its group number and module type appear in the list. The format used is the group number followed by the module type e.g. "3 MShareParam". Clicking on groups in this widget causes one of three actions depending on the current state of that module within the user's environment. If the user has a member of that group, and it is connected, then its control panel is maximised, this is the find action. If the user has a member of that group, but it is currently disconnected, then the module is reconnected, this is part of the join action. If, for some reason, the user does not have a member of that group, then an appropriate module is launched and connected to the session. This is also the join action. Connection of other COVISA modules can only occur after the successful connection of the MServer module.
MShare modules - before connection.
	These are the basic data sharing modules, one for each of the principal internal datatypes of IRIS Explorer.  MShareGeom - to share the geometry datatype. MShareLat - to share the lattice datatype. MSharePyr - to share the pyramid datatype. MShareParam - to share the parameter datatype (used by control panel widgets), and hence control of modules. This is how they look before connection, with only the Initiate button (5) and the Pass Through menu (6) visible. Pressing the Initiate button makes them connect to the COVISA Server. Setting the Pass Through widget to on means that data received on the modules input port is not only passed into the session, but also passes out of the output port of the module. When set to off, the data is only passed into the session (assuming the module is connected).
MShare modules - after connection.
	Once the modules have connected, then their control panels change to show the following information: Group Number. This number identifies the collaborating group to which this module belongs. This number is consistent in each map editor, allowing collaborators to accurately identify shared data objects. Reconnect/Disconnect toggle. This allows individual modules to be disconnected from the collaborative session to allow periods of private work.
MAdvisor
	The MAdvisor module should be launched once the MServer module has connected to the collaborative session. It is used to: aid collaborative map building; aid collaborators who may be less experienced IRIS Explorer users; and to help late joiners to a session catch up by sending them the current state of the map. It uses Skm (IRIS Explorer's scripting Language) to construct map elements in the Map Editor of other collaborators. It can do as little as launch a named module, or as much as construct an exact copy of an entire map. The labeled buttons perform the following functions: The Skm function to be applied using the text in the typein below. The text required to fulfil the Skm command as chosen by the menu above (1). For example, start just needs the name of a module entered into the typein box. The Skm action to apply to the (set of) module(s) highlighted in the map editor. This can be to copy the entire map, overlay the parameters of the highlighted module(s) onto their counterparts in the other map editors, etc. Pressing this button applies the Skm action chosen by the menu above (3) to the currently highlighted (set of) module(s). This is a list of usernames of all the current collaborators in the session (except yourself). In addition it has the default option of All. Selecting a username from this list enables the targeting of the generated Skm commands. This button is used to connect the module to the collaborative session and is only visible while the module is unconnected. Since the module connects automatically after launch this button is generally not visible.
In addition to the basic set of data sharing modules, several other collaborative modules are available.