It's an all-in-one downloadable portable that lets you browse through a large variety of the various FOSS programs that are available for Windows, conveniently sorted into their general use purpose and then with a quick easy blurb explaining what the software does and allowing you to install it with a couple of clicks.
Further, if you already have some of this software installed, it will scan your system and if there is an update available it allows you to apply all of the updates with a single click.
It has become my go-to software for setting up new computers, and I cannot recommend it enough.