And such tools are available in all modern browsers:
* Safari has the same developer tools as chrome (they're part of the Webkit package), though Safari's tend to lag, and Chrome adds some stuff not present in mainline.
* Firefox has Firebug (third-party extension) and new releases have added a few built-in console-type stuff.
* Opera has Dragonfly, it's a built-in but (in my experience) tends to "feel" flakier than either WDT or Firebug.
* MSIE has its own devtools, they're horrendously bad in MSIE8 and still pretty bad in MSIE9 (they're flaky and tend to be unstable, they're also harder to use and extremely ugly). This is probably the devtools you'll find most painful. I do not know what will be in IE10. Purely for debugging I believe you can also hook Visual Studio (including Express Edition) and get a more full-featured debugger.
Some IDEs can also do remote JS debugging, which is actually pretty freaky. IntelliJ IDEA 9.0+ (and derivatives, RubyMine, PyCharm, PHPStorm and WebStorm) can be hooked in Firefox and Chrome with a bit of setup[0].
In my experience, the Webkit tools (particularly in Chrome and Iron) are ahead of Firebug, especially when trying to debug minimized JavaScript (pretty print is included in the tool--in Firefox, you need an additional plugin). Firebug can get laggy when debugging large JS files, too.
* Safari has the same developer tools as chrome (they're part of the Webkit package), though Safari's tend to lag, and Chrome adds some stuff not present in mainline.
* Firefox has Firebug (third-party extension) and new releases have added a few built-in console-type stuff.
* Opera has Dragonfly, it's a built-in but (in my experience) tends to "feel" flakier than either WDT or Firebug.
* MSIE has its own devtools, they're horrendously bad in MSIE8 and still pretty bad in MSIE9 (they're flaky and tend to be unstable, they're also harder to use and extremely ugly). This is probably the devtools you'll find most painful. I do not know what will be in IE10. Purely for debugging I believe you can also hook Visual Studio (including Express Edition) and get a more full-featured debugger.
Some IDEs can also do remote JS debugging, which is actually pretty freaky. IntelliJ IDEA 9.0+ (and derivatives, RubyMine, PyCharm, PHPStorm and WebStorm) can be hooked in Firefox and Chrome with a bit of setup[0].
[0] http://wiki.jetbrains.net/intellij/Debugging_JavaScript_with...