In this Master Degree diploma project we analyze performance of different syncronization mechanisms of multithreaded .Net applications, developed testbench software for gathering and processing experimental data, implement fast asynchronous lock-free messaging library using C#. THREAD, PROCESS, PROCESS CONTROL BLOCK (PCB), THREAD LOCAL STORAGE (TLS), ASYNCRONOUS CALLS, ASYNC/AWAIT, CRITICAL SECTION, MONITOR, AUTORESETEVENT, MANUALRESETEVENT, SEMAPHORE, LOCK-FREE STRUCTURES