7-Zip 15.05 is still useful today, because it was the last version to include built-in support for decompiling NSIS installer scripts. The feature was removed due to security concerns.
I've not personally used it, but there's a fork that adds NSIS decompilation back in: https://github.com/myfreeer/7z-build-nsis
Why is decompiling NSIS a security concern?
what is NSIS?
I've not personally used it, but there's a fork that adds NSIS decompilation back in: https://github.com/myfreeer/7z-build-nsis