The "Debug Console" is a very usefull javascript-program that lets you test and debug your own javascript-programs very easely. It lets you survey objects, variables and functions and it's even possible to execute functions manually via console!
Developer: trueworld.ch Platform: all Date upd:2003-12-01 Hits1379 [Download] [Visit]

With this script you easly can detect which browser your visitor is using and if the browser is D.O.M. compatible.
Developer: una-designs.net Platform: Tested with: IE 4+, IE 5+, IE 6+, NS 7, Opera 7 Date upd:2003-08-15 Hits825 [Visit]

This script is used to encode / decode UTF-8 data
Developer: Justas Vinevicius Platform: Date upd:2006-09-09 Hits2136 [Download] [Visit]

A method to get the styles on an element that aren't set in-line or with JavaScript.
Developer: Justas Vinevicius Platform: Date upd:2007-02-20 Hits190 [Visit]

Tito Web Studio is a feature rich and extremely effective JavaScript Debugger and JavaScript Profiler. This enterprise grade software will help QA analysts and web developers debug and profile JavaScript related web projects. Tito Web Studio's JavaScript profiler is the first in the market.
Developer: Tito Software Platform: windows Date upd:2007-02-28 Hits878 [Download] [Visit]