maXbox is a script tool engine, compiler and source lib all in one exe
The Art of Coding: maXbox is a script tool engine, compiler and source lib all in one exe to design and code your scripts in a shellbook! It supports Pascal, Delphi (VCL), Python (P4D), PowerShell and Java Script (Edge WebView).
Decompiler for setups creates with the Nullsoft Installer
...UPDATE: It'll maybe not working on this anymore. http://7-zip.de does a great job in also decompiling NSI.So I recommand you to check out 7-zip BETA.
Generally 7-zip opens NSI[exe] files - since 9.33 [2014-06-15] there should be additionally the file [NSIS].nsi inside, that is the decompiled setup script.
Attention this NSIS decompilation was disabled in 7z 15.06.
So last version that officially **supports NSIS Script decompilation** is 7z **15.05**
https://sourceforge.net/projects/sevenzip/files/7-Zip/15.05/ (2015-06-15)
-> 7-zip 15.10 no longer decompiles NSIS script
http://bit.do/7zNoMoreNSIS
^-however doing a private build you may get it back(more details in the post).