Neo.VM is a lightweight, deterministic, stack-based virtual machine library for executing Neo smart contract bytecode, written in C# targeting .NET 10.0. It implements a complete instruction set (opcodes) for arithmetic, control flow, stack manipulation, type conversion, arrays/structs/maps, and interop (syscalls). The VM features a pluggable jump table dispatch pattern, integrated reference counting for garbage collection of cyclic object graphs, and a debugger API supporting step-into/over/out. Extensively tested with JSON-driven specification files covering edge cases, plus performance benchmarks. Published as a NuGet package, it serves as the execution engine for the Neo blockchain's smart contract runtime.