CFEclipse - An Eclipse plugin for ColdFusion
The best plugin I found, for Eclipse IDE. Simply it gears Eclipse with all-you-need for CF development: color-coding, content outline, code & bracket highlighting, code folding, tag code completion, snippets, etc... full feature list
Uber fast install:
1. Select the "Help->Software Updates->Find and install" menu option
2. On the screen that is displayed, select 'Search for new features to install' and click the 'Next' button
3. Now click the 'New Remote Site' button
4. Enter a name for the update site, for example "CFEclipse". In the URL box, enter "http://www.cfeclipse.org/update" and click the OK button
Note: This is the moment when you are going to install CFUnit too.
ColdFusion 8 Debugging
Well, not much to say but to advise you to sit and read this ADC step-by-step tutorial.