General computing term. AOT stands for "Ahead-of-time".
Wikipedia: "In computer science, ahead-of-time (AOT) compilation is the act of compiling a higher-level programming language such as C or C++, or an intermediate representation such as Java bytecode or .NET Framework Common Intermediate Language (CIL) code, into a native (system-dependent) machine code so that the resulting binary file can execute natively. AOT produces machine optimized code, just like a standard native compiler. The difference is that AOT transforms the bytecode of an extant virtual machine (VM) into machine code."
See also: JIT compilation.