Inno setup software
This isn't actually one of my downloads but so associated with VB6 project distribution that I thought it fits in best here.
Inno Setup provides a scripting language to compile a setup program for Windows applications.
For Visual Basic users, this is a useful and very versitile alternative to the "Package & Deployment Wizard", (PDW), particularly for packages with a large number of files. One of the main problems with PDW is that files have to be added one-at-time to the basic selection and there is no easy facility to create sub-folders in the installed package.
Inno allows both of these problems to be solved and has a host of other facilities not available with PDW. In fact, my only criticism is that there are so many possibilities that there is a very steep learning curve.
For anyone who's interested, I've outlined my use of Inno Setup for VB6 packages on this linked page.