Complex sentence: OS/2 VDMs are considerably more powerful than NTVDM, e.g., block devices are supported, and various DOS versions can be booted into an OS/2 VDM.
Split into simpler sentences: OS/2 VDMs are considerably more powerful than NTVDM. For example, block devices are supported, and various DOS versions can be booted into an OS/2 VDM.