The new PiDrive Foundation Edition has a custom version of the Raspberry Pi Foundation's NOOBS OS installer software on the included SD card. This version installs OSes on the PiDrive instead of on the SD card. After installation, when an OS is selected from the menu, the system will boot from the SD card, then transfer operation to the drive (run OS, apps and user data there). So the role of the drive is not just add-on storage, but it becomes the primary storage for the system (similar to how the hard drive took over main storage duties from the floppy in PC's).
In the standard version of NOOBS, various OSes are presented in the setup menu for download and installation. The NOOBS installer then re-partitions the sdcard and installs the selected OSes in the partitions. Raspbian (full version with PIXEL GUI) and Raspbian Lite (core version with command-line interface, no GUI) are two of the OS options.
In the new PiDrive version of NOOBS, Raspbian (full) and multiple instances of Raspbian Lite are presented in the setup menu. The multiple instances of Raspbian Lite are the "Project Spaces" and have predefined partition sizes from 8GB to 32GB. Up to five Project Spaces may be installed plus an additional instance of Raspbian Lite that uses the remaining space on the drive (or splits it with Raspbian-full if this is also selected for installation). So if a user chooses to install all of the menu items, upon reboot they can choose to launch Raspbian-full (with GUI, web browser, productivity and programming tools, etc.) or launch one of the Project Spaces (which will launch the instance of Raspbian Lite and start at login with command-line interface). Each Project Space (instance of Raspbian Lite) is independent, with its own config.txt, cmdline.txt and raspi-config settings. So you could use different passwords, regional settings, device names, video settings, overclocking, memory allocation, etc. for each project. Projects are created via command-line programming and users can find many, many on-line, step-by-step, instructions for creating Pi projects.
It's like having a stack of SD cards each preloaded with Raspbian Lite to start projects on, but in this case it's installed on the drive and project software runs on the drive instead of on the SD card. This may be desirable in applications with high write duty cycle or in cases where high write throughput is needed.
The PDF at the link below is a document in progress providing info on Project Spaces. It includes several example projects with detailed command-line entry. After further editing it'll be posted on the product support page.
For those that already have a PiDrive and would like to try the Foundation Edition software, please see the other forum thread announcing the PiDrive Foundation Edition 250GB, $26.99, I provided a link to the files and installation instructions in one of the posts.
Link to Project Spaces document, work in progress: