Domnic Mendes, who had a positive experience with this tool, thought OpenLaszlo would be a good addition to Cool Tools.

OpenLaszlo is the leading open source platform for the
development and delivery of rich Internet applications
on the World Wide Web.

Applications developed on OpenLaszlo provide a
dramatically improved online user experience featuring
advanced interfaces delivered on a single Web page. By
bringing true application behavior to the Web,
OpenLaszlo makes a new generation of online
communications, commerce and content services viable
for the first time.

OpenLaszlo applications are written in LZX, a
standards-driven XML and JavaScript description
language that enables a declarative, text-based
development process. LZX supports rapid prototyping,
collaborative software development and long term code
maintenance.

Depending on requirements, OpenLaszlo applications can
be deployed either SOLO (Standalone OpenLaszlo Output)
or from the OpenLaszlo Server. SOLO deployment
supports most use cases and works from any HTTP Web
server. OpenLaszlo Server deployment supports
additional data integration options, persistent
connections and run-time media transcoding. The
OpenLaszlo server is Java-based and works with leading
J2EE application servers and Java Servlet Containers.
OpenLaszlo's standards-based architecture delivers
exceptional reliability and scalability, proven in
deployments serving millions of users to date.

Benefits:

• Develop standards-based rich Internet
  applications that support any Web browser with a
  single code base in XML and JavaScript

• Deploy them from any HTTP Web server in SOLO
  mode, or from a J2EE application server or Java
  servlet container running the OpenLaszlo Server under
  Linux, UNIX, Windows or Mac OS X

• Display them in any Web browser enabled with the
  Flash 6 Player or above, reaching 96% of all
  Web-enabled desktops