The presence of these systems is totally transparent to the user. He does not experience the presence of the system while using the gadgets. This is because the operating environment only requires minimal control buttons and response panels. The embedded systems are designed completely with a different philosophy. These are not general purpose computing environments. Instead, these have dedicated mode of operation. In these cases the operating system is not aimed at raising through put with general purpose utility back-ups. Instead these systems are designed with minimal and dedicated services. The minimal service provisioning is done using a minimal OS kernel often called micro-kernel. A well known embedded system is a common mobile phone and a personal digital assistant (PDA). One important Indian contribution in this class of systems is a Simputer. A Simputer can be utilized as a PDA. Simputer can also be used in a dedicated application. Simputers have also been upgraded to support wireless connectivity.