Wellsoft
Wellsoft Corporation is an Electronic Medical Record software vendor based in Somerset, NJ.  It has been incorporated for over eighteen years, and is currently rated #1 in the KLAS Report for best EDIS (Emergency Department Information Systems) systems as of Nov 17th, 2006.
Some competitors include GE Healthcare, Siemens AG, and Cerner.  Healthcare Information Technology is one of the fastest growing fields  which has increased the number of EDIS (Emergency Department Information Systems) vendors tremendously.

# Wellsoft tracking
The Wellsoft Suite started out as DOS based "HomeEasy" Discharge Instructions.  This version is no longer deployed, although it maintains quite a few installations throughout the United States.
The recent version (Wellsoft v11) is Windows based, with optional web deployment via Citrix.  It currently uses the Oracle database (which can be deployed on Windows or Linux).
Wellsoft Tracking Display - Version 11
File:Tracking screen.png

# Web-based access
Many EDIS systems offer internet-based access, and there are two basic routes with which this can be accomplished.  Web based applications generally support thin client deployments through Java or HTML, while compiled applications typically use Citrix.  Wellsoft currently uses Citrix.
There are advantages and disadvantages to each method.  Citrix deployments are capable of running both compiled and web-based applications, however they require that a Citrix Client be loaded onto the machines.  While this is practical in an Emergency Department, it is less practical for providing access to patient information over the internet.

# Compiled Applications vs Web-based Applications
Wellsoft is a compiled application, which is web-enabled (through Citrix) but not web-based.
HTML-based applications are almost universally portable.  They can be used on any machine, with any operating system, including thin clients.  While the portability is ideal for displaying web-pages with information, the poor stability of Internet Explorer and lack of user interface control make HTML-based applications a poor choice for serious applications.
Java-based applications are very similar to compiled applications.  While it is more portable than compiled applications, Java applications are also significantly slower.  This type of application is well suited for remote doctors offices, but ill suited to time-critical tasks such as those in the Emergency Department.
Compiled applications have been optimized for a particular operating system.  While this makes compiled applications faster, it also restricts them to running on a particular operating system (for example, Windows).  In the Emergency Department this is typically not an issue, since remote access is usually less important than speed.

# Update architecture
The system updates are deployed via the server.  The workstations check the server for updates, and installation occurs automatically.  This allows update distribution to occur without taking down the system.
Wellsoft takes approximately five minutes.  However, the update time varies dramatically from vendor to vendor, with updates taking anywhere from a minute to several hours.  This is especially important in the Emergency Department, and in fact has been a barrier to entry for many other hospital-wide systems.