Does NSIS support Linux and Solaris? I read somewhere that we can compile nsis script on Linux but cant execute the .exe generated on any other platforms but Windows. Can somebody put more light in this?
The installer systems for Windows and Linux are completely different.
Whereas Windows' only contribution to a software management system is one registry entry pointing to the uninstaller, Linux has a full working software management system. There are apt, yum, pacman and many more out there, which are supporting many more features and possibilities including automatic execution of scripts and pulling in/installing dependencies. If you have a cross platform application you wanna share, you're either stuck with creating a tar-ball, or you learn how to build deb/rpm etc. packages.
You can compile installers on POSIX and windows systems, but it always produces a win32 PE file that only runs on windows (And maybe WINE)
Check the NSIS manual for more info
No.
See the NSIS feature list for more information ...
Portable Compiler
The NSIS compiler can be compiled for POSIX platforms like Linux and *BSD. Generated installer will still run on Windows only, but this way they can be generated without Windows or WINE.