I love the constraint system in OpenLaszlo too, and I've used OpenLaszlo for many projects. The "Garnet" user interface system, developed in the 90's by Brad Me

I love the constraint system in OpenLaszlo too, and I've used OpenLaszlo for many projects. The "Garnet" user interface system, developed in the 90's by Brad Meyers at CMU, also has constraints for laying out user interfaces. I worked on both Garnet at CMU and OpenLaszlo at Laszlo Systems. Here's a description and comparison of the two systems, that I wrote a while ago: Constraints and Prototypes in Garnet and Laszlo: http://www.donhopkins.com/drupal/node/69 http://www.donhopkins.com/drupal/node/69 "Once you've tasted a programming language with constraints, you will not want to go back. Programming without constraints is like writing in machine language: error prone, low level, tedious, inefficient and mind numbing." "Constraints are like structured programming for variables: In the same way that it's better to use loops and conditionals instead of gotos, it's also better to use declarative programming that says what you mean, instead of imperative peeks and pokes and side effects." A description of OpenLaszlo: What is OpenLaszlo, and what's it good for? http://www.donhopkins.com/drupal/node/124 http://www.donhopkins.com/drupal/node/124 I also worked briefly on a cross platform gui system called Galaxy, for a company called Visix, which had a constraint system called "springs and struts". But it turned out they were evil so I left. (The company, not the springs and struts. ;)