Creating Forms and its Elements with few lines of PHP code, without any HTML. Ajax support, JS-AFV (auto-form-validation). Now also with brandnew Templatesystem to reload ones filled out Forms. Ride the Lightning !!!
OpenJX is a Java XML form language similiar to Flex. In a few simple lines of XML and Javascript, a developer can create a fully featured Java application or applet. OpenJX also features a network based plugin system which is extremely powerful.
The HTML sandpit allows you to experiment with HTML, CSS and Javascript and see the results on the same page. The sandpit is tiny - a lean version is less than 40 lines of mostly HTML and a small Javascript function. The sandpit can be used off-line.
PHP-O-Lait is a library that, in 2 boiler-plate lines of code, allows you to call server-side PHP code from client-side JavaScript. It's so easy, in fact, that you don't need to know how it does it (hint, it uses Ajax and JSON).
The JSP Validation Filter was developed by the ICPC webteam at Baylor University. It is very non-intrusive in that you do not need to introduce new lines into your JSP files to validate forms.
JavaScript abstract class to manipulate (insert, delete, move) unlimited number of similar dynamic HTML form fileds on the fly (without submitting the form). Useful for CMS, table sheets of undefined number of lines or columns.
JAST (Javascript Toolkit) is an Open Source cross-platform javascript framework that aid users to perform the most hard operations with few simple lines of code.
It's modularity allow the download only for the code required to the page.