Regular Ninite installers always install the latest versions of apps. However, in some enterprise situations it's important to test new versions of apps before deployment or have a homogenous deployment of one version.
Ninite's /freeze switch lets you make fully-bundled offline installers for the current version of an app. These installers will always install the version they were frozen with and contain all the resources to install the app.
For example, let's use Ninite Pro to make a self contained Ninite Java installer:
NinitePro.exe /select Java /freeze
Ninite Pro will create a new installer .exe with the current version of Java in the name. You can freze apps like this periodically and build a collection of historic versions. This could be helpful if you need to roll-back machines to an old version or want to standardize on a fixed version even as new releases come out.