TinyOS is an open source operating system designed for wireless sensor networks. It is an event-driven OS written in the nesC programming language. Applications and libraries are built as software components that interact in an event-driven way without preemption. TinyOS uses static linking and has constraints on memory and power due to running on small embedded devices.

3. Consists of spatially distributed autonomous devices using sensors to monitor environmental conditions.

4. Small physical size and low power consumption Concurrency-intensive operation Limited Physical Parallelism and Controller Hierarchy Diversity in Design and Usage Robust Operation

5. Constrained resources Efficient multitasking Flexibility “ Mote”-class devices 10-100 kilobytes of code ROM < 20 kilobytes of RAM

6. Portability Flexibility Efficient Multitasking Networking (TCP/IP)‏ Size

8. Free and open source component-based operating system. Started as a collaboration between the University of California, Intel Research. Embedded operating system written in the nesC programming language. Event driven Operating System. Application and Libraries are written using nesC,a programming language.

9. Specifically designed for WSN. Event-driven OS. Completely non-blocking. Programs are built out of software components . Tasks are non-preemptive and run in FIFO order. Tiny OS code is statically linked.

10. Open source, highly portable, multitasking operating system. Developed by Adam Dunkels at the Swedish Institute of Computer Science. First OS for sensor networks to provide TCP/IP. Protothreads , a extremely lightweight, stackless threads.

11. Multitasking kernel Preemptive scheduling Managed Memory Allocator Protothreads TCP/IP networking, including IPv6

12. TINY OS CONTIKI OS Event –driven OS with non-preemptive multitasking . Event-driven OS with optional preemptive multitasking . Static linking . Dynamic linking. Written using nesC programming language . Written using C Programming language .

14. N etwork E mbedded S ystems C Event-driven programming language used to build applications for the TinyOS platform. An extension to the C programming language Designed to embody the structuring concepts and execution model of TinyOS.

15. Separation of construction and composition. Specification of component behaviour in terms of set of interfaces. Interfaces are bidirectional. Components are statically linked. Designed to run on embedded devices used in WSN .