Using PSPad as a NSIS editor
I know there already IDE's for NSIS, but having a seperate IDE for every language sucks.
I like PSPad (http://www.pspad.com/en/), it's free and very customisable.. It has a NSIS highligher supplied (but not one of the standard one, you need to add to it the Custom highlighters).. It works pretty well. Best of all, with a bit ot tweaking, you can compile from within the IDE enviroment, I needed to tweak the settings in the PSPad.ini, here is what I ended up with, and it works well (adjust path of NSIS and remove the /D defines from the commandline if you don't use them).
[Nullsoft Install System]
Filter=Nullsoft Install System (*.nsi)|*.nsi
HLTabWidth=0
IndentChar=
UnIndentChar=
Comment=000080001FFFFFFF010
Identifier=1FFFFFFF1FFFFFFF000
Key=1FFFFFFF1FFFFFFF100
Key words 2=1FFFFFFF1FFFFFFF100
Key words 3=1FFFFFFF1FFFFFFF100
Label=000000FF1FFFFFFF000
Number=1FFFFFFF1FFFFFFF000
Preprocessor=008080001FFFFFFF010
Reserved word=000000801FFFFFFF100
Space=008080001FFFFFFF000
String=1FFFFFFF1FFFFFFF000
Symbol=1FFFFFFF1FFFFFFF000
Compilator File=C:\Program Files\NSIS\makensis.exe
Compilator Param=/DMAJORVER=2 /DMINORVER=9 /DBUILD=4 |%File%|
Compilator LOG=
Compilator Run=
Compilator Help=
Compilator SaveAll=1
Compilator ParsLog=*on line %L -- aborting creation process ;NSIS
Compilator Capture=1
Compilator HideOutput=1
Compilator DefaultDir=C:\Program Files\NSIS