TSF and Managed Code

Dan asked whether someone could write a text service in managed code.  While I suspect that doing so is possible (but difficult), it is certainly not desirable.  Text services get loaded into arbitrary processes, so they need to be small and lightweight.  Loading the CLR into an arbitrary process is neither small nor lightweight.  Worse than that, it might not even work - there's only one CLR host per process, so if the target process is already running the CLR, it will fail.  Plus, of course, you have version incompatibility issues (between various versions of the CLR).