ZIP/LZMA licensing question

[cowwoc]

Hi,

I'd like NSIS to download optional sections in ZIP or LZMA format, then unpack them and continue with the installation. I know how to make everything work except for unpacking. The only unpacking plugin I could find for ZIP was ZipDLL but it is licensed under GPL and its readme seems to imply it is illegal to use it for installation of commercial software (which is what I want).

Alternatively, I'm thinking I could just include lzma.exe and use it to unpack files on the client end.

Is there any easier way? Is there a built-in script command which allows me to extract LZMA files? LZMA unpacking logic is built into the installation EXE so I expect to be able to use it somehow.

Thanks,
Gili