Well, the name 'Plugin' is a bit too much, but I wanted to stick to the naming convention...
UltraEdit is a nice little text editor when working on Windows. It is very much suited to handle all kinds of resource files and some little scripts, when starting your IDE just takes too long.
You can get it from http://www.ultraedit.com/
UltraEdit is not free but fairly inexpensive. One can work with the evaluation license forever, but warnings get more and more annoying then.
The first nice thing is to edit and run any groovy script from inside the editor. When doing so and getting a stacktrace, it is added to an output list that is click-aware. In the line you click, UltraEdit tries to find a filename and a line/column position and opens the editor at that position.
To make this happen, go to Advanced -> Tool Configuration and enter the following:
After that, you can run your active Groovy script with Ctrl-Shift-0.
UltraEdit is aware of those languages that are described in %INSTALL_DIR%\WORDFILE.txt. Add to that file what you find here . UltraEdit assigns numbers to its known languages (up to 20 may be defined). Groovy is numbered as 12 in the above file. If that would conflict with an existing entry, you can change that by editing the first line that reads /L12.
With that language support, Groovy code now looks like
Below the editor is the output window and right of it is a function list, that shows interesting lines of the file. The current implementation shows class and method definitions. They are clickable for easy navigation.
Hitting Ctrl-Space in UltraEdit will cause it do try some text-based code completion. It is surprising how helpful such a simple functionality can be.
UE will try to smart-indent your code while typing.
All the usual other stuff like