Specific tasks associated with debugging are performed in the background, prior to a user of an application development tool invoking the debugger. The tasks including (1) starting a hosting process, (2) loading a hosted runtime environment (e.g., .NET runtime) in the process, and (3) attaching a debugger to the hosting process, are performed in the background before the user commences debugging. Once the user invokes the debugger, the user's application is executed and debugged. Thus, the perceived time to start debugging is greatly reduced.