DOSVSE
DOSVSE is a term that can refer to several different things, primarily related to the DOS operating system environment. One common interpretation is a DOS-based extender that allows 16-bit DOS programs to access more than the standard 640 KB of conventional memory. These extenders, such as DPMI (DOS Protected Mode Interface) or VCPI (Virtual Control Program Interface), enabled applications to utilize extended or expanded memory, significantly improving performance for memory-intensive software. Without such extenders, many DOS programs would have been severely limited by the 640 KB barrier.
Another possibility is that DOSVSE is a specific, perhaps less widely known, DOS extender or a program