The Lively Kernel is an open-source web programming environment, developed by Dan Ingalls when he was at SAP Research.

[1][2] Development began at Sun Microsystems Laboratories in Menlo Park, California, and later moved to the Hasso Plattner Institute in Potsdam-Babelsberg near Berlin.

Simple graphics are thus assembled into such standard widgets as sliders, scroll bars, text views, lists and clipping frames.

Lively has been used to build simple web sites, including its own tutorial, and also a client-side Wiki system that stores its pages in a versioned repository.

Content can vary from relatively static pages of text to fully dynamic models that look and behave like Adobe Flash simulations.

Except for one small initial file, the Lively Kernel code base is entirely free of tests for which client browser is being used.

Lively includes an integrated development environment of considerable power, designed to work via WebDAV with a local set of a dozen or so source JavaScript files synchronizable with a versioned repository.

When all the source files are loaded, a rapid scan will find every reference to a selected text, and present all the code bodies that match in a separate sub-browser.

There are also facilities for debugging at error points and profiling for performance tuning, but these have not been pushed, owing to the improving quality of such run-time support in all the major browsers.