I wondered what MicrosoftManagedCode is other than a VirtualMachine where the ByteCode happens to be x86-code. But then realized that this seems to be a more or less new combination (even if it may be a step back). Is this really a new combination, or are there other OSes, that have SandBox''''''es (most have more or less sensible process isolation), GarbageCollection (not that I know of; ErosOs maybe?), ... ''Misconception: ManagedCode has nothing to do with the OS. It is simply Microsoft MarketingSpeak for SourceCode intended to run on their CommonLanguageRuntime.'' There may be a misconception, but that's not it. It may be MarketingSpeak, but it names some feature. What is this feature? It cannot be 'SourceCode' as that is surely not run (=interpreted)on the CLR. And the CLR is surely an OS feature. Now what is ManagedCode else then I stated? -------- I personally see ManagedCode as that code which executes in a runtime that provides type safety verification, GarbageCollection, rich reflection, dynamic loading, and exceptions with readable stack traces; I would not consider security or process isolation to be prerequisites. Both JavaVirtualMachine and CommonLanguageRuntime fit my description of ManagedCode. -- JeffreyHantin ''You mean ManagedCode is to VirtualMachine as MachineCode is to CPU/RealMachine?'' Not necessarily. ActiveOberonSystem would probably qualify as well, and it appears to be managed machine code; Microsoft's NGEN tool accomplishes much the same purpose. The use of a VirtualMachine is largely a means to provide simpler, more verifiable input code and allow for more extensive optimization by the runtime, possibly even PartialEvaluation of common cases. -jh ---- '''managed code''' - that is, using a language in which memory management is automatic. Java and .NET languages do this with garbage collection; VB does this with reference counting; I don't care how you do it, just let me concatenate strings without thinking about where the new bigger string will go and I'll be happy. -- JoelSpolsky ---- What does "managed code" mean to .NET programmers? Automatic memory management? A sandbox something like a "chroot jail" ? Something else entirely?